general specification - civil and building works
TRANSCRIPT
document.doc
Table of Contents
1 SUPERVISION OF CONSTRUCTION.................................................................1
2 MATERIALS............................................................................................................22.1 GENERAL............................................................................................................................................2
2.1.1 Admixtures for Concrete or Grout..........................................................................................22.1.2 Aggregates..............................................................................................................................32.1.3 Bitumen Felt...........................................................................................................................52.1.4 Bricks, Blocks and Mortar......................................................................................................52.1.5 Cement....................................................................................................................................62.1.6 Cement Grouts........................................................................................................................72.1.7 Ceramic wall and floor tiles....................................................................................................72.1.8 Cover Blocks and Spacers for Reinforcement........................................................................72.1.9 Doors, Frames and Linings.....................................................................................................72.1.10 Dowel Bars.............................................................................................................................82.1.11 Draw Cord..............................................................................................................................82.1.12 Electrodes, Filler Rods and Wires for Welding......................................................................82.1.13 Fertiliser..................................................................................................................................92.1.14 Gates and Posts.......................................................................................................................92.1.15 False Ceilings..........................................................................................................................92.1.16 Fixings for Metalwork............................................................................................................92.1.17 Flanges for Pipes and Pipeline Fittings..................................................................................92.1.18 Floor Tiles and Sheeting.........................................................................................................92.1.19 Gaskets for Flanged Joints....................................................................................................102.1.20 General Filling Materials......................................................................................................102.1.21 Glass.....................................................................................................................................102.1.22 Glazing Materials..................................................................................................................112.1.23 Granular Sub-base Material..................................................................................................112.1.24 Grass Seed............................................................................................................................112.1.25 Handrails and Balusters........................................................................................................112.1.26 Imported Topsoil..................................................................................................................122.1.27 Industrial Flooring, Walkways and Stair Treads..................................................................122.1.28 Insulation Material................................................................................................................132.1.29 Joinery Timber......................................................................................................................132.1.30 Joint Filler Board..................................................................................................................132.1.31 Joint Sealing Compounds and Sealants................................................................................132.1.32 Joint Seals and Lubricants....................................................................................................142.1.33 Ladders.................................................................................................................................142.1.34 Lime for Mortar....................................................................................................................142.1.35 Manhole Covers and Frames................................................................................................152.1.36 Marker Tape..........................................................................................................................152.1.37 Mineral Aggregates for Flat Roofs.......................................................................................152.1.38 Mortar...................................................................................................................................152.1.39 Nuts, Screws, Washers and Bolts.........................................................................................152.1.40 Paints and Painting Material for Buildings...........................................................................162.1.41 Pipes for Ducts......................................................................................................................162.1.42 Plastic Sheeting.....................................................................................................................162.1.43 Plywood................................................................................................................................162.1.44 Polyethylene Pipes and Fittings............................................................................................162.1.45 Precast Concrete Paving Flags and Paving Blocks...............................................................162.1.46 Precast Concrete Kerbs, Channels, Edgings and Quadrants.................................................16
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2.1.47 Precast Concrete Manholes and Soakaways.........................................................................172.1.48 Precast Concrete Products....................................................................................................172.1.49 Rainwater Pipes and Gutters.................................................................................................172.1.50 Roof Coverings.....................................................................................................................172.1.51 Sand......................................................................................................................................172.1.52 Soil, Waste and Ventilating Pipes........................................................................................172.1.53 Steel Pipes and Fittings.........................................................................................................172.1.54 Steel Reinforcement..............................................................................................................192.1.55 Steel Sheet Piles....................................................................................................................192.1.56 Structural Steel......................................................................................................................202.1.57 Surface Boxes and Guards....................................................................................................202.1.58 Synthetic Resin Adhesives...................................................................................................202.1.59 Timber and Preservation of Timber......................................................................................202.1.60 Tying Wire............................................................................................................................212.1.61 Unplasticised PVC (PVC-U) Pressure Pipes and Fittings....................................................212.1.62 Valves and Penstocks...........................................................................................................212.1.63 Vinyl PVC Floor sheeting....................................................................................................212.1.64 Gate Valves...........................................................................................................................212.1.65 Air Valves.............................................................................................................................222.1.66 Pressure Reducing Valves....................................................................................................222.1.67 Check Valves........................................................................................................................222.1.68 Butterfly Valves....................................................................................................................222.1.69 Eccentric Plug Valve Construction.......................................................................................232.1.70 Penstocks..............................................................................................................................232.1.71 Water.....................................................................................................................................232.1.72 Water Fittings and Appliances..............................................................................................232.1.73 Waterproof membranes for roofing......................................................................................242.1.74 Water proofing to foundations..............................................................................................24
3 EXCAVATION, BACKFILLING AND RESTORATION.................................253.1 GENERAL..........................................................................................................................................25
3.1.1 Trench Excavations...............................................................................................................263.1.2 Turf for Relaying..................................................................................................................273.1.3 Topsoil for Re-Use...............................................................................................................273.1.4 Dealing with Water...............................................................................................................273.1.5 Temporary Drains.................................................................................................................283.1.6 Backfilling............................................................................................................................283.1.7 Work Acceptance..................................................................................................................293.1.8 Reinstatement of Unpaved Land...........................................................................................30
3.1.8.1 General..............................................................................................................................303.1.8.2 Trenches.............................................................................................................................31
3.1.9 Filling Above Ground...........................................................................................................313.1.10 Blasting.................................................................................................................................313.1.11 Piling.....................................................................................................................................323.1.12 Maintenance of Reinstatement.............................................................................................323.1.13 Site Clearance.......................................................................................................................323.1.14 Landscaping..........................................................................................................................33
3.1.14.1 Site Preparation.................................................................................................................333.1.14.2 Planting..............................................................................................................................333.1.14.3 Maintenance......................................................................................................................33
4 CONCRETE AND FORMWORK........................................................................344.1.1 Concrete................................................................................................................................344.1.2 Ready-mixed Concrete.........................................................................................................34
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4.1.3 Concrete Mixes.....................................................................................................................354.1.4 Trial Mixes............................................................................................................................364.1.5 Chloride Content...................................................................................................................364.1.6 Batching and Mixing............................................................................................................364.1.7 Workability...........................................................................................................................374.1.8 Transporting, Placing and Compacting................................................................................374.1.9 Concreting in Hot or Cold Weather......................................................................................384.1.10 Concrete Temperature...........................................................................................................384.1.11 Curing...................................................................................................................................394.1.12 Records of Concreting..........................................................................................................394.1.13 Construction of Formwork...................................................................................................404.1.14 Cleaning and Treatment of Forms........................................................................................414.1.15 Striking of Formwork...........................................................................................................414.1.16 Removing the forms from concrete......................................................................................414.1.17 Sloping Formwork................................................................................................................424.1.18 Cutting and Bending of Reinforcement................................................................................424.1.19 Fixing of Reinforcement.......................................................................................................434.1.20 Surface Condition of Reinforcement....................................................................................434.1.21 Laps and Joints.....................................................................................................................434.1.22 Welding of Reinforcement...................................................................................................434.1.23 Built-in Items........................................................................................................................434.1.24 Construction Joints...............................................................................................................434.1.25 Surface Finishes Produced Without Formwork....................................................................444.1.26 Surface Finishes Produced With Formwork.........................................................................454.1.27 High Strength Concrete Topping..........................................................................................454.1.28 Tie Bolts for Formwork........................................................................................................454.1.29 Tolerance for Concrete Surfaces...........................................................................................454.1.30 Marking of Precast Concrete Components...........................................................................474.1.31 Concrete Testing...................................................................................................................474.1.32 Sampling Cubes....................................................................................................................484.1.33 Cube Strength Results...........................................................................................................484.1.34 Other Tests............................................................................................................................494.1.35 Contamination.......................................................................................................................494.1.36 Protection of Joints...............................................................................................................494.1.37 Specimen Panels of Concrete...............................................................................................494.1.38 Benching...............................................................................................................................49
5 BUILDING WORKS..............................................................................................505.1 BRICKWORK AND BLOCKWORK, GENERAL................................................................................50
5.2 BRICKWORK AND BLOCKWORK, JOINTING AND POINTING.....................................................515.2.1 Tolerances in masonry works...............................................................................................51
5.3 WATERPROOFING FOR TERRACES/FLAT ROOFS......................................................................51
5.4 THERMAL INSULATION OF TERRACES/FLAT ROOFS..................................................................52
5.5 DAMP PROOF COURSE....................................................................................................................53
5.6 BONDING TO CONCRETE................................................................................................................53
5.7 CENTERING AND LAGGING............................................................................................................53
5.8 BRICKLAYING AND BLOCKLAYING IN COLD WEATHER..........................................................53
5.9 PREPARATION FOR PLASTERING..................................................................................................54
5.10 FIXING OF PLASTERBOARD...........................................................................................................54
5.11 PLASTERING.....................................................................................................................................545.11.1 Plastering in Cold Weather...................................................................................................55
5.12 CONCRETE FLOOR FINISHES..........................................................................................................55
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5.13 SHEET VINYL FLOORS....................................................................................................................55
5.14 STONEWARE FLOORS.....................................................................................................................56
5.15 POLISHED CEMENT AND MOSAIC FLOORS..................................................................................56
5.16 CERAMIC AND QUARRY TILED FLOORS......................................................................................57
5.17 EXTERNAL RENDERING.................................................................................................................57
5.18 CARPENTRY AND JOINERY............................................................................................................57
5.19 ROOFS...............................................................................................................................................58
5.20 TIMBER FLOORS..............................................................................................................................58
5.21 DOOR FRAMES.................................................................................................................................58
5.22 ROOF TILING....................................................................................................................................58
5.23 BITUMEN FELT ROOFING...............................................................................................................59
5.24 PLUMBING........................................................................................................................................59
5.25 OPENINGS IN WALLS, FLOORS, AND CEILINGS...........................................................................59
5.26 TOLERANCES FOR BUILDING WORKS..........................................................................................60
5.27 IRONMONGERY...............................................................................................................................60
5.28 BUILT-IN ARTICLES.........................................................................................................................60
5.29 GUTTERS AND DOWNPIPES............................................................................................................60
5.30 EXTERNAL DOORS..........................................................................................................................60
5.31 INTERNAL DOORS...........................................................................................................................61
5.32 ALUMINIUM DOORS AND WINDOWS...........................................................................................61
5.33 PAINTING..........................................................................................................................................61
5.34 HANDRAILING.................................................................................................................................62
5.35 SNAGGING WORK............................................................................................................................63
6 SANITARY INSTALLATION.............................................................................646.1 MATERIALS......................................................................................................................................64
6.2 PLUMBING PIPING AND ACCESSORIES.........................................................................................646.2.1 Plumbing Piping Identification.............................................................................................64
6.2.1.1 Valve Identification............................................................................................................646.2.1.2 Piping Identification..........................................................................................................646.2.1.3 Pipe Support Spacing Schedule.........................................................................................656.2.1.4 Pipe Hanger Sizes..............................................................................................................65Gaskets 666.2.1.5 Sealing Tape......................................................................................................................666.2.1.6 Adhesive.............................................................................................................................666.2.1.7 Pipe Sleeves and Escutcheons...........................................................................................666.2.1.8 Valves and Strainers..........................................................................................................67
6.2.2 Water Meters and Other Accessories....................................................................................67
6.3 PLUMBING EQUIPMENT.................................................................................................................686.3.1 Cold Water Supply Pumps....................................................................................................686.3.2 Pipe Test and Sterilisation....................................................................................................69
6.3.2.1 General..............................................................................................................................696.3.2.2 Pressure Test for Cold Water Supply and Hot Water Pipe Work:....................................696.3.2.3 Sterilization of Installation................................................................................................696.3.2.4 Underground Drainage System.........................................................................................706.3.2.5 Aboveground Drainage System.........................................................................................70
6.3.3 Pipe Installation....................................................................................................................716.3.3.1 Layout and Arrangements..................................................................................................716.3.3.2 Preparation of Pipe...........................................................................................................716.3.3.3 Threaded Pipe Joint Makeup.............................................................................................71
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6.3.3.4 Welded Pipe Joint Make-up...............................................................................................716.3.3.5 Flanged Pipe Joint Make-up.............................................................................................726.3.3.6 Reducing Fitting................................................................................................................726.3.3.7 Unions and Flanges...........................................................................................................726.3.3.8 Installation of Water Piping..............................................................................................726.3.3.9 Sewer, Waste and Storm Drain..........................................................................................736.3.3.10 Polyvinyl Chloride (PVC) Pipe.........................................................................................736.3.3.11 Reinforced Concrete or Concrete Pipe Refer to Civil Works Specifications....................73
7 INTERNAL HEATING INSTALLATIONS........................................................757.1 PRE INSTALLATION.........................................................................................................................75
7.2 PIPE INSTALLATION........................................................................................................................75
7.3 MOUNTING THE PLANT ANCILLARIES.........................................................................................75
7.4 MOUNTING THE HEATING PLANT.................................................................................................76
7.5 HEATING PLANT..............................................................................................................................76
7.6 ACCEPTING THE WORKS................................................................................................................76
8 CONSTRUCTION OF PIPELINES AND ANCILLARY WORKS..................778.1 PIPELAYING GENERALLY..............................................................................................................77
8.2 PIPE BEDDING..................................................................................................................................77
8.3 CONCRETE PROTECTION TO PIPES................................................................................................77
8.4 COMPLETION OF PIPE SURROUND................................................................................................78
8.5 THRUST BLOCKS.............................................................................................................................78
8.6 PIPE JOINTING GENERALLY...........................................................................................................78
8.7 WELDED JOINTS IN PLASTIC PIPES................................................................................................78
8.8 FLANGED JOINTS.............................................................................................................................79
8.9 WELDED JOINTS IN STEEL PIPES...................................................................................................79
8.10 PROTECTION OF FERROUS PIPES, JOINTS AND FITTINGS...........................................................80
8.11 CUTTING PIPES.................................................................................................................................80
8.12 PRECAST CONCRETE MANHOLES.................................................................................................81
8.13 INVERTS AND BENCHING...............................................................................................................81
8.14 PIPES AND JOINTS ADJACENT TO STRUCTURES.........................................................................81
8.15 WATERTIGHTNESS OF MANHOLES AND CHAMBERS................................................................82
8.16 SETTING MANHOLE COVERS AND CHAMBERS...........................................................................82
8.17 CONNECTIONS TO EXISTING SEWERS..........................................................................................82
8.18 MARKERS AND INDICATOR POSTS...............................................................................................82
8.19 TOLERANCES FOR PIPELINES........................................................................................................82
8.20 INSTALLATION OF VALVES AND PENSTOCKS............................................................................83
8.21 LAYING CABLE DUCTS...................................................................................................................83
8.22 CONNECTIONS TO EXISTING PIPELINES.......................................................................................83
8.23 MAINTAINING WATER SUPPLIES TO CUSTOMERS.....................................................................84
8.24 LAGGING TO EXTERNAL PIPEWORK............................................................................................84
8.25 MAINLAYING AND SERVICE RECORDS........................................................................................84
8.26 PROGRESS OF PIPELINE CONSTRUCTION.....................................................................................85
8.27 WORK IN HIGHWAYS......................................................................................................................85
8.28 HYGIENE AND CLEANLINESS........................................................................................................85
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9 TESTING AND DISINFECTION.........................................................................869.1 CLEANSING OF PIPES......................................................................................................................86
9.2 PRECAUTIONS PRIOR TO TESTING PIPELINES.............................................................................86
9.3 TESTING METHOD PROGRAMME AND NOTIFICATION..............................................................86
9.4 TESTING NON-PRESSURE PIPELINES.............................................................................................86
9.5 WATER TEST FOR NON-PRESSURE PIPELINES.............................................................................87
9.6 AIR TEST FOR NON-PRESSURE PIPELINES....................................................................................87
9.7 CCTV INSPECTION OF PIPELINES...................................................................................................87
9.8 INFILTRATION..................................................................................................................................87
9.9 TESTING OF PRESSURE PIPELINES (EXCLUDING PVC AND POLYETHYLENE PRESSURE PIPES).................................................................................................................................................87
9.10 TESTING OF PVC AND POLYETHYLENE PRESSURE PIPES..........................................................89
9.11 SWABBING OF WATER PIPELINES.................................................................................................89
9.12 DISINFECTION, SAMPLING AND OPERATION OF WATER PIPELINES........................................89
9.13 CLEANSING OF STRUCTURES........................................................................................................90
9.14 TESTING OF CONCRETE ROOFS.....................................................................................................90
9.15 TESTING OF WATER RETAINING CONCRETE STRUCTURES......................................................91
9.16 DISINFECTION OF STRUCTURES FOR POTABLE WATER............................................................91
9.17 WATER FOR TESTING, SWABBING AND DISINFECTION.............................................................91
9.18 DISPOSAL OF WATER FROM CLEANSING, TESTING OR DISINFECTION...................................92
9.19 Testing of Non-Concrete Water Retaining Structures................................................................................92
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1 SUPERVISION OF CONSTRUCTION
The quality checking process shall be in conformity with the provisions of the “Technical manual of the construction”, and with the technical regulations for quality control specific to the category of works and constructions.
The findings are registered by the Engineer in the “Technical manual of the construction” and in case of defects, the time for rectification recorded, the retesting date and acceptance also recorded. When certain situations are found, exceeding the fixed statutory standards or affecting the safety of the construction, the Engineer is obliged to request a technical survey in order to start an extended quality control process, according to the regulations. This survey shall be presented to the State Inspectorate in Constructions, Public Works, Town Planning and Territorial Arrangement who may order an investigation or special watch of the project.
The Engineer is obliged to know the “Technical manual of the construction” and to keep it up to date.
The basic regulations which shall to be observed during construction are:
H.G. (Government Decision) 261/1994 – Decision regarding the approval of certain rules drawn up according to the art. 35 and 36 of the Government Order no. 2/1994 regarding the quality in constructions
H.G. 272/1994 – Decision regarding the approval of the Rules related to the state control on the quality in constructions
H.G. 273/1994 – Decision regarding the approval of the Rules related to the acceptance of the construction works and their afferent installations
Law no. 10/1995 - Law of quality in constructions
H.G. 766/1997- Decision regarding the approval of certain rules regarding the quality in constructions
H.G. 51/1992 – regarding certain measures for improving the activity of fire prevention
H.G. no. 256/1994- regarding the metrological activity in constructions.
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2 MATERIALS
2.1 GENERAL
All goods and Materials used in the Works shall comply with international standards (SR, EN, ISO) or those of the appropriate national standards body where no other standard is given, for both manufacturing and testing.
A copy of the relevant parts of the standards of the recognised National standards body shall be provided by the Contractor in English where required by the Contract, and be to the satisfaction of the Engineer.
All goods and materials to be provided by the Contractor and incorporated in the Works shall be new, unused, and of the most recent or current design and specification, and incorporate all recent improvements in design and materials, unless provided for otherwise in the Contract.
At least 28 days prior to use, the Contractor shall submit to the Engineer a list of his proposed suppliers and sources of materials required for the execution of the Works. Samples shall also be submitted at the request of the Engineer.
The materials subsequently supplied shall conform to the quality of samples which have been inspected by the Engineer.
Names of additional suppliers and sources may be submitted by the Contractor during the execution of the Contract, but no source of supply shall be changed without the Engineer's approval.
Materials and components shall be stored in such a manner as to preserve their quality and condition to the standards required by the Contract.
Materials and components shall be handled in such a manner as to avoid any damage or contamination, and in accordance with all applicable recommendations of the manufacturers.
Unless otherwise described in the Contract, the use, installation, application or fixing of materials and components shall be in accordance with all applicable recommendations of the manufacturers. Where appropriate, the Contractor shall make use of any technical advisory services offered by manufacturers.
Where not covered by the mechanical and electrical specification, all items of mechanical and electrical plant shall be installed on a reinforced concrete plinth at least 150 mm thick. Reinforcement for plinths shall be adequate to resist static and dynamic loads imposed on them including stresses arising from changes in temperature.
2.1.1 Admixtures for Concrete or Grout
Flubet or equivalent super-plasticizing additive may be used for improving working of concrete, according to the provisions of the technical instructions C 2II-82 and NE012-99, enclosure I.3.
For concrete class C16/20 (Bc20) and C20/25 ((Bc25), Flubet additive may be replaced by Disan A additive or equivalent, by observing the provisions of the enclosure I.3. of NE012-99.
Entrained air shall be determined during prior laboratory tests, in order to determine the concrete composition.
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Calcium chloride shall not be used in concrete that is to be reinforced, contain embedded metal, or has been designed to retain an aqueous liquid. Where used with sulphate-resisting cement, or in concrete which is to be reinforced or contain embedded metal, the chloride ion concrete of admixtures shall not exceed 2% by mass of the admixture or 0.03% by mass of the cement. Admixtures containing chlorides shall not be used in reinforced concrete designed to retain an aqueous liquid.
Admixtures proposed must be approved by the Engineer together with details of the concrete mixes.
2.1.2 Aggregates
Coarse aggregate for concrete and other purposes shall comply with the requirements of STAS 1667-76 or approved equivalent.
Aggregates may either be of natural gravel or stone crushed to the desired size and shall only be obtained from quarries, pits or other sources approved by the Engineer.
Gravel aggregate shall be free from clay, earth, loam or other organic or similar materials and shall be hard and dense and shall be approved by the Engineer prior to use.
Crushed stone shall be from hard rock and perfectly clean and shall contain no soft, clayey, shaley or decomposed stones. The stone shall be crushed by suitable stone crusher approved by the Engineer. Any dust or fine materials below 5 mm in size resulted in the crushing process shall be removed through screening. The screened stone obtained be thoroughly washed by a method approved by the Engineer.
Coarse aggregate containing significant portion of elongated particles shall not be accepted. The tolerable portion of the elongated particles shall be assessed by sieve method as directed by the Engineer.
The grading of coarse aggregate shall comply with STAS 1667-76 and NE 012-99 Code or approved equivalent. For reinforced concrete work, the nominal maximum shall be 7mm to 31mm.
For the 7-31 category, the passing in percentage through the 16 mm sieve shall be minimum 30% and maximum 60%. The maximum size of aggregates that remain on the upper sieve shall not exceed 1.5 dmax.
Unless otherwise directed by the Engineer, grading of the aggregates shall be as shown below:
Grading Limit% passing by weight through sieve size (mm)
0.2 1 3 7 16 31 40
0 – 7 mmmax. 12 40 70 100
min. 3 25 54 95
0 – 16 mmmax. 8 35 50 70 100min. 2 25 41 61 95
0 – 31 mmmax. 7 30 40 60 80 100min. 2 21 31 51 71 95
0 – 40 mmmax. 7 25 40 55 76 100min. 2 15 25 40 65 95
Should the grain size of the material show a deficiency in the grading specified, the Engineer shall require the Contractor to add aggregate of any particular size to change the grading to comply with the above requirements.
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Aggregate shall meet the following requirements, regarding the content of impurities:
Foreign bodies (animal or vegetable) - not permitted
clay or any other material adhering to the aggregate - not permitted
clay lumps - not permitted
mica content max. 2%
coal content max. 0.5%
The content of clay, silt and dust shall not exceed:
for sand max. 2%
for gravel max. 0.5%
for the total aggregate max.1%
Soil determined as NaOH solution, shall provide a colourless or light yellow solution.
Gravel and broken stone shall comply with the following minimum conditions, as regards the shape of the grains:
b/a 0.66 and c/a 0.33
The methods for checking the quality of the aggregates shall be determined by STAS 4606-80.
For each load delivered the Contractor shall provide the relevant documents together with the certificate of quality with the results of tests.
The Contractor’s laboratory shall examine the certificate of quality to ensure that it is in compliance with the quality certificate. If not, the batch of material will be rejected.
During transport from the supplier and storage on site, the aggregates shall be kept away from impurities or prevented from mixing with other material.
Aggregates shall be stored in concrete-based bins or on stages to prevent intermixing and the inclusion of dirt and foreign materials.
The Contractor’s laboratory shall check the quality conditions of each type of aggregate.
At point of supply these checks shall include for:
foreign bodies
clay lumps
clay, silt and dust
graininess
shape of the grains (for gravel and broken stone).
The determination shall be done for each lot and at least one sample for each 200 m 3 . If the results comply with the stipulated conditions, the aggregate may be used; if not, it shall not be used and within 48 hours shall be removed from site.
The Contractor shall check the graininess of the aggregates and the humidity, one a shift and any time necessary where the source of supply is changed.
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The Contractor shall keep evidence of the tests done for quality of the aggregates, as follows:
a file to contain all the certificates of quality issued by the supplier
a register of aggregates to contain all the results of the tests done by the laboratory on delivery
a register to contain all the results of the laboratory tests done while using the aggregates.
The Contractor shall use only fine and coarse aggregates in concrete that are considered as non-susceptible to alkali aggregate reaction. Unless historical evidence of non-susceptibility of the aggregate to alkali-aggregate reactivity is available, then a petrographic examination shall be carried out on a sample of aggregate. If potential alkali-aggregate reactivity is indicated than a mortar bar expansion test in accordance with ASTM C1260 (NBRI method) shall be carried out.
An expansion at 14 days not exceeding 0.1% will be taken as demonstrating non-susceptibility to alkali-aggregate reactivity.
Aggregates which give rise to concrete with a high coefficient of thermal expansion shall be avoided. Chert, flint and quartzite shall not be used without written approval.
2.1.3 Bitumen Felt
Bituminized felt PA 55 for foundation works shall be according to STAS 1046-97.
Bitumen for water proofing works shall be type H 68/85 and H 80/90, according to STAS 7064-78.
2.1.4 Bricks, Blocks and Mortar
Bricks shall be of dimensions 240x115x63 and shall correspond to the provisions of STAS 457-86.
Mortar and bricks for masonry shall be as follows:
NoBuilding height H
(m)
Maximum number of levels (n)
Minimum brick and mortar requirements according to seismic protection category
6 7 8 9
Brick type
Mortar type
Brick type
Mortar type
Brick type
Mortar type
Brick type
Mortar type
1 H 4 1 50 10 50 10 50 25 75 50
2 4...H…9 3 75 25 75 25 75 50 100 50
Bricks with vertical holes shall be of size 290x140x88 and 240x115x63 and be of 1st quality type 100 and correspond to the provisions STAS 5185/2086.
Bricks shall be transported in containers, to avoid breakage. No broken or fissured blocks or blocks will be accepted. They shall be stored in covered places in sufficient quantities for a continuous flux of the execution.
Bricks to be used for manholes and chambers shall be heavy duty engineering bricks to an acceptable standard.
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Air bricks and gratings for wall ventilation shall match any surrounding bricks.
All bricks shall be frost resistant where required by local conditions.
Concrete Blocks shall be of ACC and size: 600x200x200, or 600x200x125.
Blocks shall be of 1st quality and correspond to the provisions of technical agreement 010-01/12-1997.
2.1.5 Cement
Portland cement shall be according to STAS 388-68, STAS 388-80 type P 35 A, STAS 388-81 type Pa 35 or STAS 1500-70 to suit the application.
White or coloured Portland cement shall be according to STAS 7055-80 or STAS 7055-96.
For the preparation of the concrete cement I32.5 shall be used whose technical acceptance and delivery conditions are regulated through STAS 388-95, and according to the norm NE012-99, I32.5 may be replaced with another type of cement.
The cement will be stored in the concrete station in bins. One should keep evidence of the bins where each cement transport has been stored.
The duration of the storage in the bins of the concrete station will not exceed 30 days since the supplier delivers it. If this storage period is exceeded, the cement will be used only with the consent of the designer and beneficiary and depending on the mechanical strength obtained according to STAS 227/6-86, at ages of 2 days on drawn samples (when evacuating it from the bins) at most 5 days before accepting to be used.
The quality of the cement will be checked according to the provisions of the enclosure I. Each transport of cement will be used only with the consent of the laboratory and on the basis of the results of the testing regarding the setting, the volume stability and the mechanical strength at the age of 2 days.
All the materials shall be stored and handled in a manner so as to avoid their degradation and to maintain their quality.
For all cement used in structural concrete a certificate to show compliance with the relevant standard shall be submitted to the Engineer before a cement source is used.
Added pigments shall be mixed with the cement in accordance with the manufacturers instructions. The amount of added pigments shall not exceed 10% of cement by mass, except for carbon black, where the limit shall be 2%.
Cement shall be delivered in bulk or in sealed and marked bags, and shall be protected from humidity and frost.
The certified acid-soluble alkali content of cement shall not exceed 0.6% Na2 O equivalent or less.
Sulphate resisting Portland cement shall not be used in a marine or tidal environment or where there is a risk of saline intrusion.
2.1.6 Cement Grouts
Cement grout shall be used within one hour of mixing, except where containing a retardant admixture.
Sulphate-resisting cement shall not be used as a constituent of grout containing Pfa.
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2.1.7 Ceramic wall and floor tiles
Ceramic tiles shall be according to STAS 233-86
Tiles shall be transported and stored in boxes, according to the conditions STAS 9504-80 and STAS 7813-80.
Boxes shall be transported in a way which they shall be prevented from moving during transport in order not to damage the packaging or the tiles.
On site, the boxes shall be stored in piles of a maximum 1.5 m high, on level platforms or shelves, away from likely damage and humidity.
The tiles shall be taken out of the boxes only when they are used.
Ceramic Floor Tiles
Unless otherwise indicated:
Ceramic tiles shall be 300 x 300 x 8mm, of high quality, resistant to scratches and chemical agents (cleaning products etc), class V4P4 (European Norm).
Ceramic skirtings shall be 15 cm long, with a round edge to match the tiles. The materials shall be provided by the same supplier as the ceramic tiles
Dimensional tolerances: +/- 0.5 mm for the length / width +/-0.3 mm for the thickness.
Colour: from the producer’s range; it shall be determined by the Engineer, on the basis of samples for the floors and for the walls, presented by the Contractor together with the certificates of quality and warranty for the maintenance of the colour and of the glaze.
2.1.8 Cover Blocks and Spacers for Reinforcement
Cover blocks and spacers shall be designed to maintain the correct clear cover of concrete over steel reinforcement, shall be as small as possible consistent with their purpose, and of a shape acceptable to the Engineer.
Concrete cover blocks shall be manufactured with a 10 mm maximum aggregate size and otherwise produced to the same specification as the surrounding concrete. Wire shall be cast in the block for the purpose of tying it to the reinforcement.
Spacers shall be of rust-proof material and shall not produce staining, or otherwise be detrimental to the concrete or steel.
2.1.9 Doors, Frames and Linings
Unless otherwise specified external doors and windows shall be aluminium - alloy 6060 (UNI 9006-1) as follows:
external windows of coloured anodised aluminium, with thermal barrier and Thermopan glass (or equivalent).
external doors of coloured anodised aluminium with thermal barrier
profiles of extruded aluminium - alloy 6060 (UNI 9006 -1)
Interior doors shall be aluminium without thermal barrier or timber with veneer according to the Contract.
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Exterior doors and windows shall have the following characteristics:
The air, water and wind tightness shall be:
air tightness - class A3
water tightness - class E4
wind tightness - class V3
Profiles shall provide a coefficient of thermal transfer K< 2.8W/m2 degrees. Interruption of the thermal bridge shall be obtained by insulation glass fibre or similar. The minimum permitted sound attenuation shall be 39-41 dB.
Hardwood stained doors, where provided, shall be framed and ledged in hardwood frames, architraves, and beads.
Unless otherwise specified internal doors shall be solid cored with plywood veneers for painting, hung in softwood frames, and where noted shall be constructed to meet the specification for fire resistance stated in the Contract, including intumescent strips.
2.1.10 Dowel Bars
Dowel bars for expansion joints in concrete shall be mild steel.
Dowel bars shall be straight, free from burrs or other irregularities and shall have their sliding ends sawn. The sliding half of each dowel bar shall be painted with a thin coat of bond breaking compound, and the end of this shall be provided with a close fitting plastic or waterproof cardboard cap at least 100 mm long, the end 20 mm of which shall be fitted with a disc of joint filler or a pad of cotton waste.
2.1.11 Draw Cord
Draw cord for duct threading shall be 8 mm diameter 3 strand hawser laid polypropylene rope.
2.1.12 Electrodes, Filler Rods and Wires for Welding
Electrodes, filler rods and wires for welding shall be compatible with the grades of steel to be welded.
Electrodes for the manual metal arc welding of carbon and carbon manganese steel and stainless steel shall comply with EN 499.
Electrode wires and fluxes for the submerged arc welding of carbon steel and medium tensile steel shall comply with EN 756 and EN 760 respectively.
Filler rods and wires for the gas shielded arc welding of ferritic steel, austentic stainless steel and aluminium and aluminium alloy shall comply with EN 440.
Manual welding of stainless steel shall be by the inert gas tungsten arc process.
2.1.13 Fertiliser
Contractor's proposals for the use of fertilisers shall be submitted to the Engineer for approval and include details of storing, mixing and application and shall comply with the manufacturers recommendations.
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2.1.14 Gates and Posts
All fittings and steel gates and posts shall be hot dip galvanised in accordance with EN ISO 1460.
All timber for field gates and posts shall be given preservative treatment.
2.1.15 False Ceilings
False ceilings shall consist of gypsum board 200 to 250 x 120 x 0.95 cm on a frame of UW30 and CD60 profiles.
Unless otherwise stated in the Contract ceiling tiles shall be 600 x 1200 mm with a vapour barrier (PE foil or aluminium on upper most side).
Characteristics for all types of ceiling tiles
fire resistance: > 1 hour
resistant to humidity
free from deformations/cracks
weight: <12 kg/sq m
tolerances -dimensional: +/- 1 mm
2.1.16 Fixings for Metalwork
Mild steel bolts, nuts and fixings shall be hot dip galvanised in accordance with EN ISO 1460 and stainless steel bolts and nuts shall be manufactured from Grade 316S31 steel.
Stainless steel proprietary fixings shall be manufactured from Grade 316S31 steel.
Where described in the Contract, axial and shear loading tests on structural fixings in concrete or masonry shall be carried out. The safe working load shall be as described in the Contract.
Where fixings are incompatible with the material being fixed, or where dissimilar metals would be in contact with each other, suitable isolating washers and sleeves shall be used.
Stainless steel shall be used for anchors and fixings unless authorised by the Engineer, and bolt details and spacing shall be in accordance with the manufacturer's instructions.
2.1.17 Flanges for Pipes and Pipeline Fittings
Flanges for pipes and pipeline fittings shall, unless otherwise required by the Contract, comply with EN 1092: Part 2 for 16 bar nominal pressure rating.
2.1.18 Floor Tiles and Sheeting
Floor tiles shall comply with the relevant provisions of the following standard as appropriate:
Natural granite tiles
Polished tiles of natural granite with non-skidding treads for steps.
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The Contractor shall provide information on:
wearing resistance
light and radiation resistance
fire resistance (if synthetic adhesives are used)
polishing (products)
Laminated vinyl floors
Shall be traffic class 32 (medium public), with sound-absorbent treatment having minimum thickness 8.5 mm using Clic or similar system.
Flooring shall be anti-static according to STAS 7361 – 80.
2.1.19 Gaskets for Flanged Joints
Gaskets for flanged pipe joints shall be of the inside bolt circle type. Gaskets shall be manufactured from material complying with EN 681, part 1 for type W rings with a hardness range of 76 – 84. The materials for flange pipe joints shall consist of rubber insertion rings 3 mm thick produced from unreinforced rubber compound such as EPDM.
2.1.20 General Filling Materials
Hardcore shall consist of clean, hard, durable material, either broken stone, bricks or concrete, graded from 200 mm to 50 mm, and be free from extraneous matter.
Selected fill, whether selected from locally excavated material or imported, shall consist of uniform readily compactable material, free from vegetable matter, building rubbish and frozen material, or materials susceptible to spontaneous combustion, and excluding clay of liquid limit greater than 80 and/or plastic limit greater than 55 and materials of excessively high moisture content. Clay lumps and stones retained on 75 mm and 37.5 mm sieves respectively shall be excluded from the fill material.
2.1.21 Glass
Glass shall be in accordance with the following:
External glass - 6 mm thick (R compressing = 80 kg/m2 and R bending = 20 kg/m2)
Internal glass - colourless 4 mm thick.
14 mm internal space filled with inert gas.
Glass shall have the attributes:
Light transmission factor 39
Thermal transmission of direct solar light 7
Thermal radiation reflection 19
Thermal transmission coefficient 1,9 W/m²K
Medium sound insulation 35 dB
Light reflection factor 12
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2.1.22 Glazing Materials
Materials for use in glazing metal frames shall be a non-setting synthetic compound of oils, plasticisers and polymers, for gun, knife or strip application and shall contain an agent to produce a surface skin to minimise dirt retention.
2.1.23 Granular Sub-base Material
Granular sub-base material shall be natural sands, gravels, crushed rock, crushed slag, crushed concrete or well burnt non-plastic shale of uniform grading. The material shall be capable of being compacted to achieve a well knit dense layer. Stones larger than 100 mm shall be removed.
Sub-base material shall be spread evenly in layers not more than 150 mm compacted thickness and compacted to obtain a well-bound surface finish, any loose areas or segregated areas being made good by addition of fines or by removing and replacing with fresh material as directed by the Engineer.
Compaction shall be carried out by approved equipment operating on the material until a dry density of not less than 95% of the laboratory maximum dry density as measured by the 4.5 kg rammer method is obtained. The CBR value shall not be less than 25% after four days immersion in water.
2.1.24 Grass Seed
Grass seed shall be a tested blend of named varieties and certificates of purity and germination shall be provided. The blend shall suit the local conditions and take account of soil type, water content, climate and soil pH. In general grass mixtures shall aim at providing a low maintenance, slow growing grass.
Seed shall be fresh for each growing season with a germination capacity not less than 80%. Purity of mixture shall not be less than 90% and total weed seed content shall not exceed 0.5%.
Total content of other crop seeds shall not exceed 1%. All seed mixes shall be well agitated to ensure thorough mixing of species.
2.1.25 Handrails and Balusters
Handrails and balusters shall be manufactured from material complying with the relevant provisions of the appropriate standard as set out below.
MaterialHandrails Balusters
Solid Tubular Solid Tubular
Mild Steel - ISO 65 - ISO 65
Aluminium EN755 EN 515, 573-3, 754 EN 1676 EN 515, 573 -3, 754
After manufacture, mild steel and aluminium handrails and balusters shall be hot dip galvanised, both inside and outside, or anodised, as appropriate, in accordance with EN ISO 1460.
Handrailing shall be provided on all stairs, landings, platforms and floors to provide the users protection against falling. This applies to stairs with three or more rises, where each rise does not exceed 200 mm, landings, platforms and floors where a drop exceeds 200 mm, and wherever there is a risk to the user.
Handrailing shall be no less than 1100 mm above the walking level on a floor, and no less than 900 mm and no more than 1000 mm above the pitch line of a stair.
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Steel handrails shall be constructed out of Low Carbon Steel Cold Formed Circular Hollow Section Grade S275JOH to EN 10 219-1 or Mild Steel with a minimum outside diameter of 33.7 mm and 3 mm minimum wall thickness or as otherwise specified in the Contract. Handrailing shall be supplied with at least one intermediate rail (or knee rail) mid-way between the handrail (top rail) and the walking level or pitch line on a stair, or the top of any kicker plate.
Balusters for handrailing shall be constructed out of either Low Carbon Steel Solid Round to EN 10 025 Grade S275JR, CFCHS or mild steel as specified for rails. The diameter for solid shanks or the outside diameter and wall thickness of tubular shanks shall be designed to suit the most economical pitch between the balusters. Balusters shall be constructed as a single unit.
2.1.26 Imported Topsoil
Imported topsoil shall be of light or medium texture, having a pH value of between 6.0 and 7.5. Imported topsoil shall not contain stones greater than 50 mm in size, nor have a total stone content exceeding 10% by mass.
The Contractor shall submit details of source and composition to the Engineer for approval. The source shall be from land cultivated without the use of pesticides or herbicides unless specified elsewhere in the Contract.
Topsoil shall be free of weeds, roots of weeds, subsoil, and foreign matter.
2.1.27 Industrial Flooring, Walkways and Stair Treads
After fabrication, low carbon steel flooring, walkways and stair treads shall be hot dip galvanised in accordance with EN ISO 1460.
Aluminium floor plate and open mesh flooring shall be insulated from steel kerbing and supporting steelwork by self adhesive PVC insulating tape.
Flooring panels shall be not heavier than 25 kg, suitable for removal by one person and with the appropriate cut-outs to permit removal without disturbing or dismantling spindles, supporting brackets or pipework. Fixing clips shall be provided.
Flooring shall be designed to carry a load of 5.0 kN per square metre, with a deflection limited to span/200 or 10 mm whichever is the lesser.
The minimum clear width for stairs shall be 750 mm.
Open mesh flooring shall be of the type with transverse bars and a serrated top surface.
Solid floor plates shall be fixed in position by countersunk screws manufactured from a suitable non-corroding material.
Open mesh flooring units shall be secured to the supporting steelwork with proprietary clips designed for the purpose.
Stair treads shall be mild steel open type with non-slip nosing.
Floor plates shall be provided with holes for standard lifting keys.
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2.1.28 Insulation Material
Insulation shall be:
polystyrene of 50 mm to the exterior of structures
expanded polystyrene 50mm over/under concrete roofs and floors, density minimum 38kg/mc, thermal conductivity minimum 0,030W/mK
unless otherwise indicated in the Contract.
The characteristics of insulation shall be:
medium density 40kg/mc±5%,
resistance at compression ≥1kg/sq m,
coefficient of thermal conductivity λ=0.020 Kcal/mh0 C.
2.1.29 Joinery Timber
Timber for joinery shall comply with the relevant provisions of EN 942.
The sizes of sawn and processed softwood and hardwood shall comply with the relevant provisions of EN 1313.
2.1.30 Joint Filler Board
Joints in concrete shall be formed using preformed filler board except that preserved knot-free softwood may be used for joints in concrete carriageways.
Holes in preformed joint filler to accommodate dowel bars shall be accurately bored or punched out to produce a sliding fit on the dowel bars.
The material comprising the joint filler shall be of such quality that it can be satisfactorily installed in position at the joint.
Adhesives used to retain preformed joint fillers in place during construction shall have no harmful effects on concrete and, except for those used in connection with softwood fillers, shall be obtained from the same manufacturer as the joint filler.
Preformed filler for joints in structures to retain aqueous liquids shall have a maximum water absorption of 0.3% by volume and a non recovered compression set of 20% of the original thickness, both when tested in accordance with ASTM B3595.
2.1.31 Joint Sealing Compounds and Sealants
Joint sealing compounds shall be impermeable ductile materials of a type suitable for the conditions of exposure in which they are to be placed, and capable of providing a durable, flexible and watertight seal by adhesion to the concrete throughout the range of joint movement.
Two-part polysulphide-based sealants. Pouring Grade shall be applied to horizontal upward-facing joints and Gun Grade to joints of any other aspect or inclination. Other two-part polymer-based sealants of Gun or Trowel Grade shall comply with the appropriate physical and test requirements.
Primers for use with joint sealants shall be compatible with, and obtained from the same manufacturers as, the adjacent sealant. Primers shall have no harmful effects on concrete.
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Sealants and primers which will be in contact with water to be used for potable supply shall not impart to water any taste, colour, or any effect known to be harmful to health, shall comply with the Romanian standards and shall be resistant to bacteria growth.
Sealants and primers which will be in contact with sewage or sewage sludge shall be resistant to biodegradation. Sealants shall be two-part elastomeric. Sealants shall have resistance to both aerobic and anaerobic bacteriological attack. When cured the sealant shall exhibit resilience to a Shore Hardness-A of at least 25°.
2.1.32 Joint Seals and Lubricants
Elastomeric seals for pipe joints shall be obtained from the pipe manufacture and shall comply with the relevant provisions of EN 681: Part 1. For water pipelines the seals shall be type WA and for drainage purposes they shall be either type WC or WG. Within EN 681-1 there is no microbiological requirement for elastomeric seals. Hence the seals shall comply with the following:
a) the average loss in mass of the test pieces shall not exceed 3.5%
b) there shall be no greater release of carbon black or other fillers from the test set than from the control set when the surface of the specimens is lightly rubbed.
In the case of composite seals the requirements apply only to those components exposed to the contents of the pipeline or pipework.
Joint lubricants for sliding joints shall have no deleterious effects on either the joint rings or pipes, and be unaffected by the liquid to be conveyed. Lubricants to be used for jointing water pipelines shall not impart to water any taste, colour, or any effect known to be injurious to health, and shall be resistant to bacterial growth.
2.1.33 Ladders
After fabrication, low carbon steel ladders shall be hot dip galvanised in accordance with EN ISO 1460.
Stainless steel ladders for vertical fixing shall be fabricated from Grade 316S31 steel.
Aluminium ladders for vertical fixing shall be fabricated from grade 6082.
After fabrication, aluminium ladders shall be anodised.
GRP ladders shall be manufactured and tested in accordance with National regulations or standards. GRP ladders shall not be used on potable water installations.
The minimum clear width between stringers of ladders shall be 450 mm.
Unless otherwise specified, vertical ladders shall not be used. Access shall be provided using ship-type ladders with a slope of 15 degrees.
Detailed drawings of all ladders shall be submitted to the Engineer for approval before manufacture.
2.1.34 Lime for Mortar
Lime for mortar shall be according to STAS 146-78 “Lime for construction”.
Any of the two qualities of lime stipulated in the standard can be used. The apparent density of the lime paste that corresponds to the consistency of 12 cm. is indicated in fig.1.
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Quality of paste The apparent density of the lime paste (Kg/m³)
I 1250-1300
II 1301-1350
2.1.35 Manhole Covers and Frames
Manhole covers and frames shall comply with the relevant provisions of EN 124, Part 1 and have a minimum clear opening of 600 mm. Covers and frames with minimum clear openings outside the ranges in EN 124: Part 1 shall comply with that standard where applicable. All manhole covers shall have closed keyways.
Covers and frames to air valve chambers shall be ventilated type.
Manhole covers and frames may be of ductile or cast iron or other material according to the requirements of the local Authority.
Particular requirements for design loading and marking of covers are given in the Contract.
2.1.36 Marker Tape
Marker tape for buried water pipelines shall be blue PVC or polyethylene mesh or ribbon at least 50 mm wide, incorporating a corrosion-resistant tracing system.
Marker tape for buried cables shall be yellow PVC or polyethylene mesh or ribbon at least 150 mm wide. Ribbon shall be printed with the local language equivalent of the words ‘ELECTRIC CABLE’ in bold capital letters at intervals not exceeding 700m, or marked with a symbol recognised Nationally and meaning "electric cable below".
Gravity sewers laid in straight sections between manholes do not require a marker tape.
2.1.37 Mineral Aggregates for Flat Roofs
Mineral aggregates for the reflection of solar heat on flat built-up bitumen or mastic asphalt roofs shall be light coloured and consist of a hard limestone having a low moisture absorption characteristic, granite, gravel, calcite flint or feldspar, of 10 mm nominal size.
2.1.38 Mortar
Mortar shall be mixed only as and when required until its colour and consistency are uniform. The constituent materials shall be accurately gauged, allowance being made for bulking of sand.
All mortar shall be conveyed fresh to the Works as required for use. Plasticising and set retarding mortar admixtures shall be supplied with instructions for use.
2.1.39 Nuts, Screws, Washers and Bolts
Bolt lengths shall be sufficient to ensure that nuts are fully-threaded tightened in their final positions.
Where bolting is incompatible with the material being fixed, suitable isolating washers and sleeves shall be used.
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Where stainless steel nuts, bolts and washers are to be used adjacent to galvanised metallic surfaces other than stainless steel than the surfaces should be isolated with sleeves and washers of non-conductive material.
Mild steel nuts, screws, washers and bolts shall be hot dip galvanised to EN ISO 1460 unless otherwise stated in the Contract.
2.1.40 Paints and Painting Material for Buildings
Paint remover shall be non-flammable, solvent-based.
All painting materials for one operation shall be compatible and shall be obtained from one manufacturer.
2.1.41 Pipes for Ducts
Pipes, joints and fittings for buried ducts (vitrified clay, concrete, or PVC-U) shall have flexible mechanical joints.
All cable ducts shall be fitted with draw cords.
2.1.42 Plastic Sheeting
Plastic sheeting for waterproof underlay shall be free from tears and voids and be substantially free from pinholes and other discontinuities. It shall have a nominal film thickness of 125µm.
2.1.43 Plywood
Plywood for general use shall comply with EN 315 and EN 635
2.1.44 Polyethylene Pipes and Fittings
Polyethylene pressure pipes for use for cold potable water in nominal sizes 90 - 1000 mm shall be as set out below:
a) ISO 4427 - polyethylene pipes for water supply - specificationsb) ISO/DIS 8085 Parts 2 and 3, pr EN 12201 - plastic piping systems for water supply -
polyethylenec) Blue PE (below ground) - cold potable waterd) Black PE (above ground) - potable water above ground or sewagee) Blue HPPE/PE 100 - potable water underground
2.1.45 Precast Concrete Paving Flags and Paving Blocks
Precast concrete paving flags shall be hydraulically pressed. Unless otherwise described in the contract, paving flags shall be 50 mm thick.
2.1.46 Precast Concrete Kerbs, Channels, Edgings and Quadrants
Precast concrete kerbs, channels and edgings shall be hydraulically pressed. Where kerbs or channels are required to be laid to a radius of 12m or less, components of the appropriate radius shall be used.
Where relevant all precast kerbs, channels, edging and quadrants shall comply the requirements of the Contract.
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2.1.47 Precast Concrete Manholes and Soakaways
Precast concrete manhole and soakaway units of circular cross section. Units which bed into bases shall be manufactured so that imposed vertical loads are transmitted directly via the full wall thickness of the unit. For joints between units and the underside of slabs, joint profiles shall be capable of withstanding applied loadings from such slabs and spigot-ended sections shall only be used where the soffit of the slab is recessed to receive them.
Chamber sections shall be precast reinforced concrete and shall interlock with each other. Precast cover slabs are to be capable of withstanding a single wheel load of 5.0 tonnes.
Precast concrete manholes and soakaways shall be manufactured to give Class 4 sulphate resistance. Sulphate resisting cement shall not be used in a marine or tidal environment or where there is a risk of saline infiltration into sewers.
2.1.48 Precast Concrete Products
Constituent materials of precast concrete products shall comply with the relevant requirements of this Specification, unless detailed elsewhere in the Contract.
Except where otherwise specified in a relevant standard or described in the Contract, the surface finish of precast products shall be Rough Finish for surfaces next to earth and elsewhere Fair Finish.
Precast concrete units shall be so handled, stacked, stored and transported that they are not subject to undue stress or are damaged in any way. No unit shall be built into the work until it has matured for 28 days. Units will be rejected if they have any of the following defects:-
a) Broken edgesb) Cracks (other than hair cracks)c) Repairsd) Honeycombing or air holes
Nominal cover to all reinforcement shall be agreed by the Engineer and will vary according to service conditions. The minimum shall be 25 mm.
2.1.49 Rainwater Pipes and Gutters
Rainwater pipes, gutters, fixings and accessories shall comply with the following appropriate standard:
Material Standard
Cast iron
Aluminium
PVC-U
Pressed steel
As per particular requirements
EN 612
EN 607
EN 612
2.1.50 Roof Coverings
Roof coverings shall comply with the following appropriate standard:
Material/type Standard
Clay tiles and fittings
Concrete tiles and fittings
EN 538, EN 1304
EN 490 and EN 491
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Material/type Standard
Fibre cement slates
Fibre cement sheets
Metal roofing – zinc
Metal roofing – copper
Metal roofing - Sheet Steel
Metal roofing – aluminium
EN 492
EN 494
EN 501
EN 504
EN 505
EN 507
2.1.51 Sand
Sand for concrete and mortar shall be according to STAS 1667-76.
Sands for bedding brick and block paving shall be sharp sands or crushed rock fines, not more than 10% being retained on a 5mm sieve and evenly graded containing not more than 3% by mass of clay, silt and fine dust. All sands shall be washed sands.
The grading of the sand shall be according to the table below.
Maximum grain
% passing in great quantity through the sieve Ø mm
0,2 1,0 3,15 7,1
Min.3 Min. 25 Min.51 Min 95
Min.12 Min.40 Min 70 Min. 100
2.1.52 Soil, Waste and Ventilating Pipes
Soil, waste and ventilating pipes, fittings and accessories for above-ground drainage systems shall comply with the following standards:
Material Standard
PVC-U (soil & ventilating)
Polypropylene (waste)
PE – HD
ISO 3633 or EN 1329
ISO 7671
ISO 8770
2.1.53 Steel Pipes and Fittings
Steel pipes, fittings and joints shall comply with the requirements of EN 10224 "Specification for steel pipes, joints and specials for water and sewage".
Pipes shall be grade 430 and manufactured by a seamless process to ISO 2604 Part 2 - TS9 Cat.ll or submerged arc welded process to ISO 2604 Part 6 - TSAW 9 Cat Vl.
External corrosion protection shall be provided with a minimum thickness of 6 mm. The exposed ends of the pipe shall be given a protective coating of bitumen primer. The coating shall be given an external limewash coating. Alternative external coatings of polyethylene or polypropylene wrapping, or thermosetting fusion bonded dry powder epoxy coating will be required if stated elsewhere in the Contract.
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Pipe ends shall be protected from corrosion with bitumen, minimum 3 mm thick, suitable for potable water where appropriate.
Internal corrosion protection shall be of concrete, cement mortar or other approved material. Pipe lining material shall be suitable for potable water or sewage as appropriate.
2.1.54 Steel Reinforcement
Steel reinforcement used in Reinforced Concrete shall conform to the requirements of STAS 438/1-89 or approved equivalent. Types and characteristics are summarized below.
Type of BarNominal Diameter
(mm)Yield Point
(N/mm2)Ultimate Strength
(N/mm2)
OB376 – 12 255
36014 – 28 235
PC526 – 14 360
51016 – 28 340
Miscellaneous metal embedded in the concrete shall conform to the requirements of STAS 8542-89 or approved equivalent unless otherwise specified.
The nominal dimensions and unit weights of bar designation shall be in accordance with STAS 438/1-89 as given below:
Diameter d (mm)
Tolerance (mm)
Sectional area (cm2)
Nominal perimeter (cm)
Nominal weight (kg/m)
6±0.3
0.283 1.88 0.2227 0.385 2.20 0.3028 0.503 2.51 0.39510
+0.3- 0.5
0.785 3.14 0.61712 1.130 3.77 0.88814 1.540 4.40 1.21016 2.010 5.05 1.58018 2.540 5.65 1.99020 3.140 6.28 2.47022
+0.5-0.8
3.800 6.91 2.98425 4.910 7.85 3.85028 6.160 8.80 4.840
Steel fabric reinforcement shall be welded at the intersections and, unless otherwise described in the Contract, shall be delivered to the site in flat sheets.
Steel reinforcement shall be obtained from firms holding a valid Certificate for Approval for the manufacture and/or fabrication of steel reinforcement issued by an approved Certifying Authority.
Steel reinforcement shall be free from loose scale, rust, oil, grease or other material at the time of fixing and placing of concrete.
2.1.55 Steel Sheet Piles
Steel from which steel sheet piles are rolled shall comply with EN 10025.
Maximum rolling margins shall be 4% above and 2.5% below the calculated masses and 75 mm over and 50 mm under the required lengths.
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Before being driven, permanent steel sheet piles shall be wire brushed to remove loose rust and dirt and be coated with black tar based paint, except that piles in contact with water to be used for potable water supply shall be coated with black bitumen solution.
2.1.56 Structural Steel
All structural steel shall comply with the provisions of STAS 500/12-80.
All steel shall be supplied with Certificates of Quality and be marked by the supplier.
Certificates of quality shall be available for inspection at the place of manufacture and include chemical analysis and mechanical test results.
Tests required are:
Strength according to STAS 200-75;
Bending at cold temperatures according to STAS 777-80;
Other tests according to STAS 1400-75, STAS 7511-81. The selection of test-pieces shall be done according to the provisions STAS 7324-75.
Internal surface faults of steelwork shall correspond to part 2.2 in STAS 767/0-77.
2.1.57 Surface Boxes and Guards
Covers for surface boxes on water pipelines shall comply with Authority requirements and have the wording detailed in the Contract cast into the top. Stop tap covers shall comply with relevant Authority requirements. They shall be capable of supporting a 5-tonne wheel load and shall accommodate a ductile iron cover.
Surface boxes for valve and penstock spindles shall be ductile iron and shall have a minimum clear opening of 135 mm and a minimum depth of 100 mm unless given elsewhere in the Contract. Spindles/extension spindles to valves or penstocks shall terminate between 250-380 mm below ground level.
Stop tap chambers shall provide continuously variable height adjustment up to 150 mm without recourse to cutting. The top of the meter shall be at 300-450 mm depth below finished surface.
2.1.58 Synthetic Resin Adhesives
Synthetic resin adhesives for plywood and wood shall be phenolic and aminoplastic and comply with EN 301 and EN 302.
2.1.59 Timber and Preservation of Timber
All timber used in the permanent works shall be new. Timber of structural use shall be of general structural grade. Softwood to be used for structural purposes shall only include those general structural grade timbers in strength to EN 338.
All structural timber shall be double vacuum pressure treated with an approved preservative.
Softwood for carpentry shall be straight, free from insect or fungus attack, sapwood, shakes, twisting and warping.
Timber shall be stored clear of the ground and under cover so as to allow circulation of air.
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2.1.60 Tying Wire
Tying wire for steel reinforcement shall be 1.6 mm diameter annealed mild steel wire.
2.1.61 Unplasticised PVC (PVC-U) Pressure Pipes and Fittings
Unplasticised PVC pressure pipes joints and fittings shall comply with the following standards
ISO 4422 parts 1 to 5 - for water supply
EN 1452 parts 1 to 5 - for water supply
EN 12842 - DI fittings for PVC-U or PE pipe
Pipes for below-ground use for potable water and having an outside diameter less than 75 mm shall be coloured blue.
Unplasticised PVC pipes, joints and fittings for gravity sewers and drains shall comply with the relevant provisions of ISO 4435 or EN 1401-1.
2.1.62 Valves and Penstocks
The Contractor shall submit full details of valves with manufacturer's drawings to the Engineer and obtain his approval before manufacture is commenced. All valves shall be individually tested by the manufacturer for both strength and leakage.
2.1.63 Vinyl PVC Floor sheeting
Vinyl PVC homogeneous sheeting shall be 2.0 mm thick with glass fibre or other approved reinforcement. Sheeting shall be polished after laying.
2.1.64 Gate Valves
Gate valves shall be of the straight through type, suitable for 16 bar working pressure. Valves shall be double flanged, drilled to PN16 as defined in ISO 2531. For potable water applications, gates shall be resilient faced up to 300 mm diameter and metal seated above 300 mm diameter. Gates shall be cast iron to EN 1561 EN-GJL-250 min or ductile iron to EN 1563 EN-GJS-450-10. For sewage applications, gates shall be metal seated.
For resilient faced gate valves, the gate shall be entirely encapsulated with rubber, Nitrile/EPDM, with a minimum 3 mm of rubber in the seating area.
For metal seated gates both the body and the gate rings shall be gunmetal and components shall be designed to provide adequate seating performance before and after wear of the seating surfaces.
Valves shall close on non-rising spindles. Bodies shall be of cast iron with stems of high tensile brass or stainless steel machined to fit gunmetal stem nuts. Stuffing boxes and necks at the bottom of spindles shall have gunmetal bushes. The stem shall have at least two "o" rings which shall be replaceable while the valve is open and under full working pressure.
The gates of valves shall be bronze and of double disk assembly.
The body and bonnet shall be cast iron to EN 1561 EN-GJL-250 min or Ductile Iron to EN 1563 EN-GJS-450-10 min.
Valve stems shall be threaded sufficiently to allow the gate to be raised clear of the nominal bore of the valve.
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Valves shall be designed to pass potable water, raw water, crude sewage or other fluid as appropriate to the Works.
Valve caps shall be of ductile iron secured by hexagon headed bolt or cap screw passing vertically through the cap on to the end of the spindle.
Unless stated otherwise in the Contract by-passes or gearboxes are not required.
Direction of closure shall be clockwise. The direction of closing shall be indicated by an arrow cast on the upper face of the gland or stem seal housing.
2.1.65 Air Valves
Air valves shall be suitable for 16 bar working pressure and be manufactured of cast iron to EN 1561 Grade 250 or ductile iron to EN 1563 and EN 1564 (ISO 1083) Grade 420/12. Floats, guides and levers shall be formed by injection moulding of Acrylonitrile Butadiene Styrene or similar approved material.
Double orifice air valves shall be designed to exhaust large amounts of air during filling, to release small amounts of accumulated air during operation, and to admit large amounts of air upon impending vacuum during draining.
An isolation valve shall be provided between the pipeline and the air valve body. Isolation valves on double orifice air valves shall be suitable for tee key operation vertically from above.
Single orifice air valves shall have a PN 16, DN 80 flange or a ¾" threaded BSP Taper male ferrule. Double orifice air valves shall have a PN 16, DN 80 flange or greater.
2.1.66 Pressure Reducing Valves
Pressure reducing valves (PRV) shall be suitable for 16 bar working pressure and be constructed of cast iron to EN 1561 Grade 220/260 or ASTM A 126 Class B. The ported guide, seat ring and trim shall be of gun metal Grade LG2C or stainless steel to AISI grade 303. The valve shall be capable of operation in any position and shall incorporate only one flanged cover at the valve top from which all internal parts shall be easily renewable. All controls and piping shall be of non-corrosive construction. Valves shall be double flanged.
2.1.67 Check Valves
Check valves shall be suitable for 16 bar working pressure and shall be suitable for potable water use. Valves shall be double flanged.
2.1.68 Butterfly Valves
Butterfly valves shall be suitable for 16 bar working pressure and comply with EN 593 and be suitable for mounting in any position. The materials of construction shall be as follows:
Body - Ductile iron to EN 1563.
Disc - To EN 1563, Zinc-free bronze or stainless steel having edges machined with rounded corners and polished to a smooth finish. The valve disc shall rotate through an angle of 90° from fully open to closed.
Shaft - Machined from stainless steel.
Valves which are to operate in throttled positions shall be metal seated. For all other duties, butterfly valves shall be of the resilient seated type and shall be airtight when shut off at all operating pressures. Seat materials shall be suitable for use in contact with potable water.
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2.1.69 Eccentric Plug Valve Construction
Eccentric plug valves shall be of the non-lubricated type with a bolted bonnet. Valves shall be suitable for 16 bar working pressure and be double flanged. Valve bodies shall be cast iron to EN 1561 grade 220 with nickel welded seals. The plug shall be a single piece casting in ductile iron to EN 1563 and EN 1564. The plug shall turn through 90o from fully closed to fully open. When fully open the plug shall be completely out of the line of flow.
The valve shaft seals shall be designed so that they can be repacked without removing the valve bonnet.
Valves to be used as control valves shall have rectangular section ports to give a control characteristic approaching a straight line.
2.1.70 Penstocks
Cast iron penstock doors and frames shall comply with EN 1561.
Frames shall be fitted with guides to steady the doors when opening. Sealing joint faces shall be either gun metal cushioned on cork or bronze and seated on a sealing compound before securing. Sealing strips shall be easily replaceable without the need to remove the penstock from the installation. Wedges shall be of cast iron and incorporate a method of adjustment to facilitate accurate setting. The penstock shall have a rising spindle with the spindle nuts of gun metal or bronze. Spindles shall be of grade 316 stainless steel with a minimum breaking stress of 378 MPa. Extended spindle steady bushes shall be the self lubricating type. Wall brackets, footplates and headstocks shall be in cast iron.
2.1.71 Water
Water for use with cement, or in contact with potable water pipelines and installations, shall be obtained from a water authority's supply and be of potable quality.
The Contractor shall make all arrangements for the supply of potable water for use in the Works, and obtain agreement from the relevant Utility. The Contractor shall provide the Engineer with a copy of correspondence confirming that the appropriate arrangements have been made before any water is extracted from the mains supply.
Where mains water is not available, the Contractor shall arrange for an adequate supply of suitable water. Water for use with cement and manufacture of concrete, including curing, shall be tested and be shown to be suitable.
Chloride, sulphate and acid soluble alkali (as equivalent Na20) contents of water shall be determined when necessary and taken into account when computing the total content of these substances in a concrete mix.
2.1.72 Water Fittings and Appliances
Water fittings and appliances shall be as follows and shall comply with the relevant by-laws and standards as appropriate:
All sanitary fittings shall be white glazed porcelain, complete with installation fixture, taps, overflows, waste outlets, plugs, traps, flushpipes, WC seat and lid, etc. Sink/drainer units shall be stainless steel with a roll front edge to match adjacent worktops.
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2.1.73 Waterproof membranes for roofing
Unless otherwise indicated roof waterproofing to flat roofs shall comprise 2 layers as follows:
Under layer - bituminous membrane PPP 2.8 –3.2mm, with braid of polyester non-woven fibre, finished on the upper side with sand, with cold-flexibility minimum -10 degrees C; applied through heat-fusion
Top layer - bituminous membrane SBS 4.5 kg/sq m, with braid of polyester non-woven fibre, finished on the upper side with slate chippings, with cold-flexibility minimum -10 degrees C ; applied through heat-fusion.
A vapour barrier of bituminous membrane type APP, thickness 2mm shall be applied through heat-fusion and jointed with bituminous adhesive.
2.1.74 Water proofing to foundations
Bituminised felt PA 55, according to STAS 1046-97.
Bitumen for hydro insulation works shall be type H 68/85 and H 80/90, according to STAS 7064-78.
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3 EXCAVATION, BACKFILLING AND RESTORATION
3.1 GENERAL
The Contractor shall carry out his operations in such a manner as to avoid damage to, or deterioration of, the final surfaces of excavations.
Excavation in streets shall be carried out in accordance with all relevant regulations and be to not less than an internationally acceptable standard.
If the Contractor encounters ground in the formations that he considers unsuitable, or if the formation is damaged or allowed to deteriorate, he shall notify the Engineer.
The sides of excavations shall be adequately supported at all times and, except where described in or permitted under the Contract, shall not be battered.
The Contractor shall be responsible for the disposal of surplus excavated material off site but no excavated material suitable for re-use in the Works shall be removed from the Site except on the direction, or with the permission of the Engineer.
Unsuitable ground, voids or damaged surfaces below formation shall be excavated and then filled to formation level with the material specified in the Contract or approved by the Engineer.
The Contractor shall notify the Engineer without delay of any permeable strata, fissures or unusual ground encountered during excavation.
The work shall be carried out by the Contractor in such a way as to avoid disturbance to the surrounding ground. Particular care shall be taken to maintain stability when executing in close proximity to existing structures and services. The work shall be carried out in a careful manner to ensure that the exposed surfaces are as sound as the nature of the material permits.
When excavations have been taken out accurately to the profiles or dimensions required for the work, the Contractor shall inform the Engineer so that he may carry out an inspection.
The Contractor shall obtain approval for excavations prior to placing material, fill or concrete.
The Contractor shall maintain open excavations in an acceptable condition, and shall rectify the effects of deterioration due to weather.
Any topsoil stripping or excavation shall only be undertaken after specific measures for dealing with pernicious plants have been taken.
Unsupported excavations may be constructed with sloping sides to a depth up to 2.0m (earth with natural moisture content 12-18%), the slope of the sides (the tangent of the inclination angle to the horizontal) shall not exceed the maximum values permitted for different categories of earth.
sand, ballast 1/1
argillaceous sand 1/1.25
sandy clay 2/3
clay 1 /2
loess 4/3
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friable rock 2/1-4/1
reef 4/1-7/1
Support of excavations with depth up to 5.0 m shall be done using steel supports according to current norms.
The Contractor shall prepare and submit to the Engineer a Method Statement for all excavations except for minor excavations where the Engineer considers such a Method Statement is not required.
28 days notice shall be given by the Contractor to the relevant Authority detailing depth, material and disposal procedures for spoil arising from excavations.
3.1.1 Trench Excavations
Trenches in rock for pipes up to 100 mm nominal bore shall be excavated to provide a minimum clearance of 100 mm around the outside of pipe barrels and joints. For pipes with nominal bores exceeding 100 mm, the minimum clearance shall be increased to 150 mm for flexible pipeline and to 200 mm for rigid pipeline.
Trench excavation shall be performed by the use of hand tools and approved mechanical equipment, in such a manner as to minimise disturbance of the sides and bottom of the excavation.
Trenches for pipes shall be excavated to a sufficient depth and width to enable the pipe and the joint, bedding, haunching and surround to be accommodated.
Joint holes shall be dug by hand below the bed of the trench in advance of the pipe being laid in the trench, or bedding where specified, to ensure that each pipe is supported throughout the length of its barrel and to enable the joint to be made, and to ensure satisfactory backfilling of the hole by hand after the joint has been made.
The Contractor shall carry out excavation in a safe manner such that the sides of the trench are adequately supported and stable.
The Contractor shall leave a clear adequate space between the edge of the excavation and the inner toes of the spoil banks.
Trenches shall not be excavated too far in advance of pipe laying and shall be sufficiently wide to allow prior and efficient jointing to be carried out in clean and dry conditions. Due allowance shall be made for bedding and surrounds.
Where pipes are required to be bedded directly on the trench bottom, the final surface shall be trimmed and levelled to provide even bedding of the pipeline and shall be free from all extraneous matter that may damage the pipe, pipe coating, or sleeving.
The widths of trenches crossing roads, or at other locations as directed, shall be as narrow as practically possible. The maximum width measured between undisturbed soil in trench sides shall not exceed the outside diameter of the pipe being laid plus 550 mm for pipes up to and including 800 mm in diameter and plus 750 mm for pipes over 800 mm in diameter.
From the bottom of the trench to a level 300 mm above the crown of the pipe, or the uppermost pipe in a dual trench, the trench width shall not be less than pipe external diameter plus 150 mm each side for a single pipe and for a dual trench the minimum width shall be (d1 + d2) + 600 where d1 + d2 are the nominal diameters and minimum clearance between barrels is 300 mm.
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Pipe trenches shall as far as practicable be kept free of surface or ground water.
When excavating trenches in carriageways or surfaced footpaths the Contractor shall first cut through the surface asphalt etc, to a straight accurate edge, by a method to be approved by the Engineer, excavate the hard material and deposit it clear of general trench excavated material, for re-use in reinstatement or disposal as directed by the Engineer.
The Contractor shall not, without the express permission of the Engineer, at any time excavate along excessive or unreasonable lengths of highway as appropriate to the site location. As a section of pipeline is laid along such section, backfilling and reinstatement shall be completed and all excavated materials surplus to the requirements of the Contract removed from the site and all constructional materials moved forward as the work proceeds, with the intent that the use of all the highway affected is restored to the public with the minimum of delay. The Contractor must take all precautions that are necessary to prevent the breaking away of the trench edges.
When excavating trenches other than carriageways the Contractor shall first remove all turf and topsoil for re-bedding or, if the turf is non-existent, all topsoil to the working width, and deposit clear of general trench excavated material for use in reinstatement.
All excavated material shall be deposited so that it is not stockpiled on topsoil and will do as little damage and cause as little inconvenience as possible.
The Contractor shall excavate trial holes by hand or machine as reasonably required for the work and shall refill and reinstate such trial holes following inspection by the Engineer.
3.1.2 Turf for Relaying
Turf to be re-laid shall measure approximately 1m by 300 mm when cut and shall be of uniform thickness not less than 40 mm.
Turf shall be green when cut; turves shall be kept moist and shall be re-laid in suitable weather conditions.
The level of topsoil beneath turf shall be such that the final grass surface after compaction shall be flush with the adjoining surface.
3.1.3 Topsoil for Re-Use
Topsoil shall mean the top layer of soil that can support vegetation. It shall include all turf not required for relaying or not acceptable for turfing.
All topsoil shall be stripped from those areas affected by temporary and permanent works including compound areas and stored for re-use.
Topsoil for re-use shall not be stacked more than 1.5m high.
The Contractor shall store topsoil for re-use local to the area of stripping so as to ensure it can be returned as near as possible to its point of origin. All other material or overburden is to be stacked separately.
3.1.4 Dealing with Water
The Contractor shall not allow water to lie in any part of the Works unless required to do so under the Contract. Water arising from or draining into the works shall be drained or pumped to an approved disposal point. Any drainage sumps required shall, where practicable, be sited outside the area excavated
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for the permanent Works, and shall be re-filled with lean mix concrete to the level of the underside of the adjacent permanent Works.
The Contractor shall take all necessary precautions to prevent any adjacent ground from being adversely affected by loss of fines through any de-watering process.
The Contractor shall take all necessary precautions to prevent any ground water from entering pipelines to be used for the conveyance of potable water.
The Contractor shall not, without the consent of the Engineer, rely upon pumping from drainage sumps as the sole means of fulfilling his obligations in dealing with water.
The Contractor shall control the manner and quality of water dealt with by pumping from drainage sumps such that there shall be, in the opinion of the Engineer, no adverse effects to the Works or to any adjacent property.
No new or existing pipes in any permanent work shall be used for the purpose of carrying water away from the excavation without permission, in writing, from the Engineer.
The Contractor shall provide the Engineer details of silt traps or other measures to be undertaken to minimise the discharge of solids arising from dewatering operations.
The Contractor shall take every precaution to ensure that his operations do not adversely affect the surrounding groundwater aquifer, or the stability of the surrounding ground or any adjacent structure.
During the construction of the Works the Contractor shall ensure the levels of the groundwater are lowered sufficiently below the proposed formation to provide a firm foundation.
The Contractor shall not begin the works without the Engineer’s consent.
The Contractor shall take all necessary measures to prevent groundwater rising during the construction of the pipelines and structures until sufficient mass of structure or backfill to pipelines has been completed to overcome any buoyancy effect.
3.1.5 Temporary Drains
Where temporary drains are required, they shall be laid in a narrow trench or grip formed below the bottom of the excavation in an approved position. The pipes shall be open-jointed and shall be surrounded with free-draining granular material.
Grouting pipes shall be inserted in the line of the temporary drains at intervals not exceeding 25m and the drains shall be solidly filled with grout, the grout pipes being cut off on completion.
3.1.6 Backfilling
Backfilling shall, wherever practicable, be undertaken immediately the specified operations preceding it have been completed. Backfilling shall not, however, be commenced until the works to be covered have achieved a strength sufficient to withstand all loading imposed thereon.
Backfilling shall be done immediately after removing the shuttering and be based on method statements drawn up by the Contractor, and approved by the Engineer.
Compaction of the fill shall comply with the following parameters:
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d.min. = 1.64 t/m3 (0.97 Normal proctor)
Wopt = 16-22%
Backfilling shall be in layers of thickness of 15 cm (deviation ±2cm) measured on the foundation’s walls.
The moisture content of the fill material shall be checked before compaction and it shall be N=16-22; no material shall be used (W 22%).
Backfilling around permanent Works shall be undertaken in such manner as to avoid uneven loading or damage.
Filling material to excavations not situated in highways or prospective highways shall be deposited in layers not exceeding 250 mm unconsolidated thickness and compacted to form a stable backfill.
Where the excavations have been supported and the supports are to be removed, these, where practicable, shall be withdrawn progressively as backfilling proceeds in such a manner as to minimise the danger of collapse, and all voids formed behind the supports shall be carefully filled and compacted.
If the Contractor's working space undermines any structure, he shall backfill under the structure with lean mix concrete.
No backfilling shall be placed around water retaining structures until the structure has been satisfactorily tested or before the Engineer's consent is obtained.
If the Contractor obtains the Engineer's consent to place backfill around the walls of the structure before it is satisfactorily tested for watertightness then the Contractor shall excavate and replace any of the backfill which is necessary in order to search for any leakage and subsequent remedial work.
In forming embankments the Contractor shall make due allowance for subsidence.
Compaction of embankments shall only take place when adjacent structures are able to resist the additional loads imposed.
In the event of subsidence taking place the method of working adopted to bring the embankments to the required levels shall be to the approval of the Engineer.
Backfill under structures shall be compacted well graded, granular fill.
Small manually-manoeuvered compaction plant will be required to ensure that the granular materials are well compacted up to the edges of the excavation.
The Contractor shall not leave timbering or other excavation-support materials in excavations after backfilling unless otherwise approved by the Engineer.
3.1.7 Work Acceptance
General
Any deficiencies found of the excavations and embankments shall be noted in the Construction works book “Record of hidden works” together with any remedial measures directed by the Engineer.
Allowable tolerances
The permitted deviation from the technical specifications for the materials (sand, ballast, gravel or crushed stone) used for backfilling and compaction of the excavation are:
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Grading ±5%
Compaction degree
- medium 2%
- minimum 5%
Permitted deviations of the compaction degree from the technical specifications are:
Type of work Average deviation Minimum deviation
General filling 10% 15%
Round the foundations of the basements and under the floor
5% 8%
In pipe trenches 5% 8%
Acceptance
The dimensions and the levels shall be checked for each excavation when completed.
The record of hidden works signed by the Engineer (for the beneficiary), and Contractor shall include:
deviations from the technical specifications
laboratory testing done below the foundation datum (at least one at 200 sq m excavation surface and 3 minimum for each object).
Testing shall be done for each layer and for the entire depth of the filling by taking a sample for each 50-100m3 of compacted earth.
Checking of all the characteristics of compaction shall be done according to STAS 1913/13-1983.
The results shall be recorded in the record of hidden works.
Remedies
The Engineer will decide when the requirements of the specifications are not met and the remedial measures required.
The cost of any remedial works shall be met by the Contractor.
3.1.8 Reinstatement of Unpaved Land
3.1.8.1 General
On completion of work in unpaved land the Contractor shall break up the surface of all land affected, to a depth of at least 300 mm, before replacing top soil, and shall cultivate and restore the land as closely as possible to its original condition.
Surfaces to be sown with grass seed shall be reduced to a fine tilth and cleared of stones and extraneous material greater than 50 mm in size. The seed shall be sown at the proper seasons, evenly distributed and applied at a rate of not less than 6g/m2 on level surfaces and 10g/m2 on sloping surfaces.
Surfaces to be turfed shall be prepared as for seeding. The approved turves shall be placed, butted, interlocked and tamped and the joints filled with fine sandy soil. On sloping ground where they may be
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likely to slip, turves shall be laid diagonally. Any subsidence taking place shall be made good by taking up the turf, filling with good finely-sieved top soil and replacing the turf in the manner specified above. Any turf that dies shall be replaced with new turf.
Reinstatement of unpaved land shall be carried out by the Contractor as follows:
Subsoil shall be ripped and broken up to an agreed depth (not exceeding 450 mm) over the whole area of stripped topsoil, as directed by the Engineer. Due regard shall be given to the location of shallow drains and services.
Topsoil shall be replaced and graded to finished ground profiles including provision of any necessary additional topsoil.
Stones and other debris shall be removed and disposed to tip.
The work shall be carried out during weather conditions which the Engineer considers to be suitable.
A general fertilizer shall be applied in accordance with the manufacturer's recommendations.
The Contractor shall be responsible for the first mowing of all grassed areas.
The Contractor shall at his own expense re-seed all areas in which seed is not, in the opinion of the Engineer, thriving reasonably well.
Permanent reinstatement of boundary crossings shall be commenced immediately the final land reinstatement works are complete unless otherwise directed by the Engineer.
Unless otherwise detailed, all banks and ditches shall be formed and graded to the original profile. Banks shall be formed using well consolidated subsoil material as a core, with a minimum 100 mm depth of topsoil cover.
3.1.8.2 Trenches
The Contractor may, in order to allow for settlement, slightly overfill backfilled trenches but the overfilling shall not be so great as to cause danger or hindrance. Should the reinstated surface sink below the level of the adjacent ground the Contractor shall make good the sinkage with productive soil.
3.1.9 Filling Above Ground
Embankments and other areas of fill shall be formed of suitable materials capable of normal compaction to form a stable fill, deposited and compacted as soon as practicable after excavation, in layers of thickness appropriate to the compaction plant used.
The filling shall, where practicable, be built up and compacted evenly, and shall be maintained at all times with a sufficient camber or cross fall and a surface sufficiently even to enable surface water to drain readily from it.
All topsoil, organic material and pockets of soft material shall be removed from all areas to be filled.
Material for filling shall be placed in layers not exceeding 250 mm.
3.1.10 Blasting
The written consent of the Engineer shall be obtained for each proposal of the Contractor to use explosives.
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Where blasting is proposed adjacent to a building or other structure, existing or under construction, the Contractor shall ensure that the agreed safe values of vibrational amplitude and peak particle velocity will not be exceeded.
The Contractor shall comply with National Codes and Regulations in the vicinity of static and mobile radio transmitters, including normal radio and television broadcasting stations and radar units associated with aircraft movements.
The handling, transport and use of explosives shall be in accordance with National Codes and Regulations and the manufacturer’s recommendations.
3.1.11 Piling
Installation and durability of piling shall comply with the relevant National practices.
Piling operations shall be strictly confined to the specified or permitted working hours and periods. Ground vibrations and noise levels shall not exceed the specified limits and the Contractor shall be responsible for taking measurements at the specified frequencies to confirm compliance.
At least four weeks prior to commencing any stage of the Works involving sheet piling operations, the Contractor shall submit his proposals in writing to the Engineer. The proposals shall include details of the type of plant to be used, the method of installation and extraction, the sequence of operations and the working periods.
3.1.12 Maintenance of Reinstatement
Until the expiration of the Defects Notification Period the Contractor shall regularly and frequently inspect all reinstatements carried out by him in connection with this Contract to ensure the safety of the public at all times.
Where deterioration or settlement of a surface occurs, whether this be noted by the Contractor during a routine inspection or be reported to him in some other manner, the Contractor shall immediately make good the defect in a manner approved by and to the entire satisfaction of the Engineer and, if applicable, the relevant Highway Authority.
Where the Contractor, or a Specialist Sub-Contractor employed by him, has carried out the final reinstatement of trenches in roads and footpaths the trenches will be subject to a joint inspection by the Engineer, the Highway Authority Engineer and the Contractor six months after completion of the works and the Contractor will be required to carry out, at his own expense, such works as may be ordered to remedy any deterioration other than fair wear and tear that may have occurred since completion.
Notwithstanding the requirement for an interim inspection the Contractor shall maintain a regular and frequent inspection of the reinstatements during the whole of the Defects Notification Period and make good any defects that may occur.
3.1.13 Site Clearance
Site clearance shall not commence until the Site fencing has been erected and is complete.
The Contractor shall not burn brushwood or other combustible rubbish on site unless otherwise approved by the Engineer.
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3.1.14 Landscaping
The Contractor shall ensure that landscaping is carried out at an appropriate season and in suitable weather conditions as approved by the Engineer. Planting operations shall be suspended in periods of drought, when the soil is frost bound or waterlogged, or in periods of persistent drying cold winds.
3.1.14.1 Site Preparation
Grass Seeding and Turfing
The area shall be cultivated to a minimum depth of 100 mm by a mechanical rotovator or similar approved method. Stones over 500 mm in any linear dimension shall be removed. All weeds shall be removed. The area is to be lightly firmed and raked to provide a fine tilth 25 mm in depth. All finished levels shall be even running levels and conform to contours or spot levels shown on the drawings.
3 to 5 days before seeding or turfing an approved pre-emergent weed killer is to be applied to the area according to the manufacturer’s instructions and an approved general pre-germination fertiliser is to be applied to the area at the recommended rate and worked into the surface tilth.
3.1.14.2 Planting
Sowing and Planting
Grass seeding shall take place only during suitable weather conditions as approved by the Engineer
The approved seed mixture shall be applied at the recommended rate and application. After sowing the ground is to be raked or chain harrowed and lightly consolidated by rolling with an approved flat roller.
If the seed fails to germinate the Contractor shall re-seed in whole or in part until a good even sward is obtained.
When the grass is 75-100 mm high and about two days before topping, the area shall be lightly rolled. Topping shall be by a roto-scythe and reduce the height of the new grass to 50 mm.
Heavy swathes of cuttings shall be removed from the newly grassed area. A second cut at a period of no less than one month after the first shall be undertaken, again to reduce the height of the grass to 50 mm followed by two cuts by cylinder mower at periods of no less than two weeks, the cuttings being removed. Immediately following the fourth cut or at a time directed by the Engineer, the newly grassed area shall be evenly dressed with an approved fertiliser.
3.1.14.3 Maintenance
Any grassed areas which fail to grow satisfactorily will be re-sown or re-turfed as directed by the Engineer after suitable ground preparation.
Tree stakes, ties and stays shall be replaced as necessary to ensure adequate support.
Rabbit guards and fencing shall be maintained throughout the period.
The bare soil areas around trees, shrubs and hedges shall be kept weed and grass free.
The Contractor shall water all grassed areas, hedges, trees and shrubs as necessary.
All dead twigs or water shoots appearing on the bare stems of trees shall be removed.
Hedging plants shall be pruned at appropriate times to encourage bushy growth. Similarly shrubs shall be pruned, to promote good form, in accordance with good horticultural practice.
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4 CONCRETE AND FORMWORK
4.1.1 Concrete
The Contractor shall design and form all concrete to meet the requirements of this Specification and the associated service conditions. These requirements are directed to the achievement of durability as well as strength.
The concrete shall be designed to resist chemical attack by the water and soil into which it will come into contact. Evidence of this design, using internationally recognised codes, shall be submitted to the Engineer.
Relevant Romanian normatives and standards are:
NE 012-99- Practice code for executing the works of concrete and reinforced concrete
Normative C56-85 - Normative for checking the quality and reception of works of construction and installations.
Concrete tests shall be carried out according to STAS 1275-88, STAS 6652/1-82 and Norm C26-85.
4.1.2 Ready-mixed Concrete
Where concrete is to be obtained from a ready-mix supplier, the Contractor shall obtain the Engineer's approval of the source and shall satisfy the Engineer that the supplying plant is capable of producing concrete to the required standard.
The Contractor shall also inform the Engineer what alternative suppliers are available to him if the approval of the source referred to above has to be withdrawn by the Engineer during the currency of the Contract.
The delivery ticket required for each load of ready mixed concrete shall detail:
the grade or mix description of the concrete
the specified workability
the minimum cement content
the maximum free water/cement ratio
the quantity of concrete in cubic metres
the time of loading
the type and nominal maximum size of aggregate
the type or name and proportion of any admixture,
the actual cementitious content and the percentage of any pfa or ggbs included
the position of the concrete in the Works.
All delivery tickets shall be kept at the Site and shall be made available for inspection by the Engineer.
The full requirements for the materials and workmanship specified herein, including all sampling, testing and returns, shall apply equally to concrete mixed on site as to ready-mixed concrete.
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Water shall not be added to concrete in a truck mixer drum other than at the batching plant. The mix shall be continuously agitated during transportation. The transportation and placing times shall be reviewed and rigidly enforced in relation to the circumstances of distance and risk of traffic delays I transit.
4.1.3 Concrete Mixes
The concrete to be used in the Works shall be of the various classes shown on the Drawings or otherwise indicated. The mix requirements for each class of concrete which may be used are as follows (C l 40-86,annex V2)
ClassWork-ability
Cement Type
Max AggSize
(mm)
Cement content(kg/m3)Water Cement Ratio Aggregates
(Dry State)(kg)
Water(l / m3)I II III
W / C W / C W / C
Bc 3.5 L2 25 71 105 2115 140(B50) 1.5Bc 7.5 L2 25 31 180 1990 160(B100) 0.88Bc 7.5/ P4 L2 35 31 300 300 320 1835 180(B100/P4) 0.6 0.6 0.6Bc 10 L3 35 31 240 255 275 1920 185(B150) 0.80 0.74 0.68Bc 15 L2 35 31 245 265 285 1950 170(B150/P8) 0.69 0.64 0.59Bc 20 L3 35 16 320 355 380 1775 205(B250) 0.61 0.57 0.53Bc 22.5 L3 35 16 380 410 440 1725 210(B300) 0.57 0.53 0,49Bc22.5/P8 L3/L4 35 16 450 450 480 1650 220(B300/P8) 0.50 0.50 0.50Bc 25 L3 40 16 355 385 415 1745 205(B330) 0.57 0.54 0.50Bc 25/P8 L3/L4 40 16 390 420 450 1675 220(B330/P8) 0.50 0.50 0.50Bc 30/P8 L3/L4 45 16 440 440 470 1660 220(B350/P8) 0.52 0.48 0.44
Concrete mixes designed by the Contractor shall take adequate precautions against the risk of cracking from thermal contraction and shrinkage and alkali-aggregate reactivity.
At least four weeks before any concrete works are proposed, the Contractor shall submit to the Engineer, and obtain his approval before concreting commences, the following information:
1. The nature and source of each constituent material.
2. The source of supply of concrete and any alternative sources that may be used.
3. Details of all concrete mixes such as:-
concrete grade
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the proposed proportions or quantity of each constituent per cubic metre of fully compacted concrete
air content of air-entrainment if applicable
chloride, reactive alkali and sulphate contents
target workability
a) Details of the proposed general method of construction, striking times of formwork, the methods of placing concrete, and the size and sequence of concrete pours.
b) The proposed methods of curing concrete.
The Engineer shall be informed of any changes to the source of constituent materials or their proportions.
4.1.4 Trial Mixes
Unless existing data on materials and properties of concrete mixes are available, preliminary laboratory tests shall be carried out to determine that the mixes satisfy the specification with the available materials.
Where field trial mixes are required, three separate batches of concrete shall be made using materials typical of the proposed source of supply and, where practicable, under full scale production conditions.
The workability, air content and density of each of the trial batches shall be determined and three cubes made from each batch for test at 28 days. The average 28-day strength of the three trial mixes shall not be less than the design target mean strength.
4.1.5 Chloride Content
Calcium chloride or admixtures containing calcium chloride shall not be used in the production of reinforced concrete or concrete which is to contain embedded metal.
The total estimated content of chloride ion by mass of cement in reinforced concrete or concrete which is to contain embedded metal shall not exceed the following limits:
Portland cement concrete, or combinations with pfa and ggbs 0.3%
Concrete made with sulphate-resisting cement 0.2%
Steam-cured and prestressed concrete 0.1%
4.1.6 Batching and Mixing
Cementitious components and aggregates shall be batched by mass to within ±2% of the target batch masses. Water and admixtures shall be batched by volume to within ±1% of the target batch volumes.
Due allowance shall be taken of the moisture content of the aggregates when batching the aggregates and water.
Mixing shall be by a forced impeller action pan mixer or horizontal axis drum mixer. The batch quantities shall be between 30% and 60% of the rated capacity of the mixer.
The time of mixing shall not be less than 2 minutes and shall be sufficient to produce a concrete of uniform colour.
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4.1.7 Workability
Workability of fresh concrete shall be such that the concrete can be handled and placed without segregation and, after compaction, can completely fill the formwork and surround all reinforcement and ducts.
4.1.8 Transporting, Placing and Compacting
Concrete shall be transported from the mixer and placed in the Works as rapidly as practicable by methods which will prevent the segregation or loss of any of the ingredients and will maintain the required workability. It shall be deposited as nearly as practicable in its final position and all equipment for transporting concrete shall be kept clean.
The Contractor shall give to the Engineer not less than 24 hours written notification of his intention to pour concrete.
Concrete shall be thoroughly compacted in its final position within 30 minutes of discharge from the mixer, unless carried in purpose-made agitators operating continuously, when the time shall be within 2 hours of the introduction of the cement to the mix and within 30 minutes of the discharge from the agitator.
The plant used for compaction shall be operated continuously during the placing of each batch of concrete until the expulsion of air has virtually ceased, and in a manner which does not promote segregation of the ingredients.
Whenever vibration has to be applied externally, the design of formwork and disposition of vibrators shall be such as to ensure efficient compaction and to avoid surface blemishes.
Placing shall not be commenced until the fixing and condition of reinforcement and items to be embedded and the condition of the containing surfaces or formwork have been approved.
Concrete shall be transported by means which prevent contamination (by dust, rain etc), segregation or loss of ingredients, and shall be transported and placed without delay.
The height of concrete to be placed in one pour shall be agreed with the Engineer before placing commences.
Concrete shall be placed directly in its final position without displacement of the reinforcement, embedded items and formwork.
The size and sequence of pours in either precast units or in situ concrete, and the sequence of erection and in situ connection of precast units, shall be arranged in such a manner as to minimise internal and external restraint and associated thermal and shrinkage cracking. Detailed methods shall be set out by the Contractor in his method statements.
Vibration shall not be applied directly or indirectly to concrete after the initial set has taken place, nor shall it be used to make concrete flow in formwork.
Placing in each section of work shall be continuous between construction joints. The Contractor shall make provision for standby equipment. If the placing of concrete is delayed by more than 30 minutes due to breakdown then the Contractor shall erect vertical stop ends and form a construction joint or remove the concrete already placed and restart after repair of the breakdown, as directed.
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Placing shall not take place in the open during storms, heavy rains or snow. If such conditions are likely to occur the Contractor shall provide protection for the materials, plant and formwork so that work may proceed. If strong winds are prevalent, protection from driving rain and dust shall be provided.
The Contractor shall agree a casting sequence with the Engineer at least 7 days before placing concrete. The Contractor shall cast concrete bays sequentially and shall avoid infill panels.
4.1.9 Concreting in Hot or Cold Weather
Valid Romanian standards and normatives:
Normative C 16-84 Normative for cold periods - construction works and installations.
a) Cold Weather Conditions
Concreting at ambient temperatures below 2oC may be carried out only if the following conditions are met:
i) aggregates and water used in the mix shall be free from snow, ice and frost;
ii) before placing concrete, the formwork, reinforcement and any surface with which fresh concrete will be in contact shall be free from snow, ice and frost and shall be at a temperature above 00C;
iii) the initial temperature of the concrete at the time of placing shall be at least 50C;
iv) the temperature at the surface of the concrete shall be maintained at not less than 5 oC at any point until the concrete reaches a strength of 5 N/mm2, as confirmed by tests on cubes matured under similar conditions;
v) temperatures at the surface of the concrete shall be measured where the lowest temperature is expected.
The Contractor shall take precautions to prevent the temperature of any concrete falling to 0 oC during the first five days after placing.
b) Hot Weather
The resultant temperature of the combined materials in any batch of concrete at the point and time of delivery to the Works shall not exceed 6oC above the prevailing shade temperature, when the latter is above 2loC.
The Contractor shall not permit any cement to come into contact with water at a temperature greater than 60oC.
Where the temperature of the fresh concrete is likely to exceed 32oC, concreting shall not be permitted, unless measures are taken to keep the temperature below that level.
c) The Contractor shall not place concrete during heavy rain.
4.1.10 Concrete Temperature
The resultant temperature of the combined materials in any batch of concrete at the point and time of delivery to the Works shall not exceed 6oC above the prevailing shade temperature, when the latter is over 21oC.
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Where the temperature of the fresh concrete is likely to exceed 32oC, concreting shall not be permitted unless measures are taken to keep the temperature below that level. These measures may include, but not be restricted to the following:
a) cooling the mixing water
b) shading the materials
c) spraying the aggregates with water
d) painting the plant white
4.1.11 Curing
Concrete shall be cured for a period not less than 7 days when the ambient temperature is 20 oC or greater by methods that shall ensure that cracking, distortion and efflorescence are minimised.
In cold weather, when the temperature of freshly placed concrete may approach 0C, alternatives to water curing shall be used.
Components which are intended to have a similar exposed surface finish shall receive the same treatment.
The Contractor shall prepare and submit detailed method proposals for curing of concrete and maintaining the curing regime. Concrete shall be wet cured or water based membrane cured for a minimum period of 7 days. The method proposals shall be to the approval of the Engineer and the approved methods will be rigorously enforced.
During the curing period measures shall be taken to prevent the loss of moisture and to minimise thermal stresses caused by the difference in temperature between the surface of the concrete and the core of the concrete mass and promote sustained hydration of the concrete. Attention is drawn to the necessity for thorough and continuous curing, particularly in the case of concrete containing Pfa or Ggbs.
For water based curing membranes: spray applications shall be applied within one hour of striking formwork and shall be of a type approved by the Engineer. Application shall be at the rate recommended by the manufacturer. In hot sunny weather, light reflecting membranes shall be used if the Engineer considers it necessary. Sprayed-on water based curing membranes shall not be used on surfaces to which concrete is subsequently to be bonded or subsequently painted.
The Contractor shall take precautions against plastic shrinkage cracking of newly formed concrete surfaces. These precautions may include, but not be limited to the following:
a) shading newly cast surfaces
b) prompt application of polythene sheeting to reduce evaporation
c) erecting wind breaks.
4.1.12 Records of Concreting
The Contractor shall keep up to date records of the dates and times when concreting is carried out and of the weather and temperatures at those times. The records shall be available for inspection by the Engineer.
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4.1.13 Construction of Formwork
Wooden formwork shall be timber in accordance with STAS l949-86, Quality C or plywood for external works in accordance with STAS 7004-89, Type A. Quality I of B or l5 mm thickness or plywood for good wagons CF STAS 8841-90.
Countersunk screw for wood shall comply with STAS 1452-80 or threaded nails to STAS 2 l 11 -90 Type B or nails from steel wire Type D.
Steel formwork shall be in compliance with STAS 500/l -89 and 500/3-80.
Valid Romanian normative and standards to be followed:
Normative C l 6-84 - Normative for achievement during cold period of construction works and installations.
Normative C 162-73 - Normative for making up, execution and use of metallic formwork for walls from in situ concrete.
Normative C 11-74 - Technical instructions for the making up and use in construction of plywood panels for formwork.
Formwork shall be sufficiently rigid and tight to prevent loss of grout from the concrete and to maintain the correct position, shape and dimensions of the finished work. It shall be so constructed as to be removable from the cast concrete without shock or damage.
The forms shall be capable of producing a consistent quality of surface as described in the Contract.
Where holes are required in forms to accommodate projecting reinforcement, fixing devices or other built-in items, precautions shall be taken to prevent loss of mortar matrix.
Formwork shall give access for the preparation of joint surfaces before the concrete has hardened.
For the purposes of compliance with the provisions of this specification, the Contractor’s method of constructing formwork shall allow for props to soffit forms to remain in position continuously for the period described.
Metal ties or anchors within the formwork shall be so constructed or sleeved so as to permit either their complete removal or their removal to a depth of at least the minimum specified cover from the face without damage to the concrete. All fittings for removable metal ties shall be of such design that, upon removal, the cavities left are of the smallest possible size. The cavities due to either partial or complete removal of ties shall be roughened and filled with a material approved by the Engineer.
Formwork panels shall have true edges for accurate alignment and shall be fixed with either vertical or horizontal joints. Where chamfers are required the fillets shall be cut to provide an even line. Joints shall not permit leakage of grout, nor steps and ridges in exposed surfaces. Due allowance shall be made for deflection of formwork during concrete placement.
Wrought formwork shall be steel panels, GRP, plywood or other suitable materials to produce a fine finish. Individual panels shall be arranged in a uniform pattern.
Rough formwork shall consist of sawn boards, sheet metal or any other suitable material which will prevent the undue loss of grout when the concrete is vibrated and produce a concrete surface suitable for the application of any specified protective coating.
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Unless otherwise indicated on the drawings all exposed arisses shall be chamfered 25mm x 25mm.
The Contractor shall take every precaution in the selection and use of forms and in removing the forms and curing the concrete to prevent rapid temperature variations in the concrete.
4.1.14 Cleaning and Treatment of Forms
The interiors of all forms shall be thoroughly cleaned out before any concrete is placed. The faces of the forms in contact with the concrete shall be clean and treated with a suitable release agent, where applicable.
Not less than 4 hours notice shall be given for the inspection and approval of the formwork and reinforcement.
Where a concrete surface is to be permanently exposed, only one release agent shall be used throughout the entire area. Release agents shall be applied evenly and contact with reinforcement and other embedded items avoided. Where the concrete surface is to receive an applied finish, care shall be taken to ensure the compatibility of the release agent with the finish.
4.1.15 Striking of Formwork
The following Romanian standards are applicable for removal of formwork to soffits of beams and slabs and props to beams and slabs - Normative C140-86 STAS 1275-88; C162-73; C11-74; C16-84; STAS 1949-96; STAS 7004-89; STAS 500/1-89; STAS 500/2-80; STAS 500/3-80; STAS 2111-90; STAS 1452-80.
Formwork shall be removed without shock to or disturbance of the concrete. If frost is possible formwork shall not be removed until the in-situ concrete has a strength of 5 N/mm2.
Formwork to vertical surfaces or sloping formwork not supporting concrete in flexure shall not be removed until the concrete strength shall be sufficient to meet any wind loading upon the concrete likely to arise at the time when the formwork is removed; and
the in-situ concrete strength (as confirmed by tests in cubes cured under representative conditions e.g. cubes alongside the formwork or temperature-match cured cubes) has reached 5 N/mm2 or;
for concrete containing only Portland cement, in the absence of cube test results a minimum period shall have elapsed since the concrete was poured equivalent to 8 hours at 20oC for unsealed plywood forms, or 6 hours at 20oC for impermeable forms.
Formwork supporting concrete in flexure shall not be removed until:
the in-situ concrete strength (as confirmed by tests on cubes cured under representative conditions) has reached 10N/mm2, or twice the stress to which the concrete will then be subjected, whichever is the greater or;
for concrete containing only Portland cement, in the absence of cube test results or any formal procedure agreed in writing with the Engineer, the periods before striking calculated from the relevant formula given in the following table shall be used:
4.1.16 Removing the forms from concrete
If the project does not stipulate other conditions, the minimum terms for removing the forms from concrete will be the ones presented in the table 4.5.
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Table 4.5.
Removing the forms from concrete
Minimum term for removing the forms from concrete
-days for the environmental temperature* -
+5 +90 C +10 +150 C > +150 C
Removing the forms from concrete from the side faces
4 3 2
Removing the forms from
concrete from the inferior faces of
the forms by maintaining the
safety props
Bridging, beams with an opening
of £ 6m10 8 6
Beams with an opening of ³ 6m
14 12 8
Removing the safety props
Bridging, beams with an opening
of £ 6m24 18 12
Beams with an opening of ³ 6m
32 24 16
* the minimum temperature on the interval for maintaining the concrete form, measured at 8 a.m.
The Contractor shall give adequate notice to the Engineer of his intention to strike formwork.
After removal remedial work shall not be undertaken until the concrete has been inspected and approved.
Before striking formwork or applying loads to concrete the Contractor shall ensure that the concrete is able to withstand stresses induced.
The formwork striking times may be assessed by one of the alternative methods below, if approved by the Engineer:
maturity measurements
penetration tests
pull-out tests
break-off tests
4.1.17 Sloping Formwork
Top formwork shall be provided to slopes 30o or more from the horizontal
4.1.18 Cutting and Bending of Reinforcement
Cutting and bending of reinforcement shall be in accordance with ISO 4066 and shall be done without the application of heat and in a temperature of not less than 5oC. Bends shall have a substantially constant curvature.
Reinforcement shall not be straightened or rebent without the approval of the Engineer. If permission is given to bend projecting reinforcement, care shall be taken not to damage concrete and to ensure that the radius is not less than the minimum specified in ISO 4066.
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At the discretion of the Engineer, a number of reinforcement bars may be required to be tested independently at a laboratory approved by the Engineer and test certificates obtained indicating the following: chemical composition, tensile strength, elongation and bend test values. To this end, the Contractor may be required to supply an extra bar of each diameter for three different shape codes.
4.1.19 Fixing of Reinforcement
Reinforcement shall be firmly supported in position and secured against displacement.
Non-structural connections for the positioning of reinforcement shall be made with tying wire or other fixing devices. Precautions shall be taken to ensure that projecting ends of ties or clips do not encroach into the concrete cover.
Reinforcement shall be held in position during the placing of concrete by use of distance pieces, spacers or other methods approved by the Engineer. Only approved spacers may be used in permanent works. Before spacers are approved for use in the works, their capacity to hold the reinforcement securely in position during concreting without detriment to concrete placement, compaction or durability shall be fully demonstrated.
Links shall be taut so that bars are braced and the inside of their curved parts shall be in contact with the bars being connected.
Partially-set concrete adhering to exposed bars during concreting operations shall be removed.
4.1.20 Surface Condition of Reinforcement
Concrete shall not be placed until reinforcement is free from any substance which might adversely affect the steel or concrete chemically or reduce the bond.
4.1.21 Laps and Joints
Laps and joints in reinforcement shall be made only at the positions described and detailed in the construction documentation, reviewed by the Engineer.
4.1.22 Welding of Reinforcement
Reinforcement shall not be welded on Site except where described in or permitted in the Contract Documentation. All welding procedures shall be subject to the prior approval of the Engineer in writing.
4.1.23 Built-in Items
Where pipes, sleeves, water bars or other items are built into concrete, they shall be rigidly secured in position to prevent movement and shall be free from external coatings which might reduce the bond. The Contractor shall take precautions to prevent the formation or air pockets, voids or other defects whilst the concrete is being placed.
4.1.24 Construction Joints
Contraction joints shall be made only at the positions described and detailed in the Contract or as reviewed by the Engineer.
Joint lines shall be arranged to coincide wherever possible with features of the finished work.
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Concrete placing shall not be interrupted except where joints occur, and shall continue after normal hours if necessary to achieve this.
Concrete shall not be allowed to taper off to a thickness of less than 50mm. Vertical joints shall be formed against a stop board suitably notched to accommodate the reinforcement. The top surface of each lift of concrete shall be straight and level unless described otherwise in the Contract.
Where a kicker is used, it shall be at least 70mm high and shall be cast monolithically with the previous concrete.
The surface of any concrete against which new concrete is to be cast shall be free from laitance and shall be roughened to the extent that the large aggregate is exposed but not disturbed. The joint surface shall be cleaned immediately before the fresh concrete is placed against it.
Where practicable, such preparation of joints shall be carried out when the concrete has set but not hardened.
Construction joints shall be located and the sequence of placing arranged as approved to minimise shrinkage and thermal strains to the concrete.
Upon removal of the formwork the joint face shall be inspected, and if the soundness of the concrete is not approved by the Engineer the Contractor shall investigate and remedy defects.
Where a design joint includes a continuous waterstop, concrete shall be well worked around the embedded part of the waterstop and be free from honeycombing. Projecting portions of the waterstop shall be protected from damage during operations and, in the case of rubber and plastic, from light and heat.
To minimise leakage at construction joints in water retaining structures adjacent panels shall be concreted within 3 days. If this is not achieved the procedure for bonding new concrete to old shall be adopted.
Where it is necessary to bond new concrete to old, the bonding agent to be used shall be an epoxy based bonding agent used in accordance with the manufacturer’s instructions. The existing concrete surface shall first be wire brushed or hacked and cleaned to remove all dirt, dust, loose material and laitance and to expose the aggregate. If oil or grease has affected any area this shall be removed by chipping away down to unaffected material.
4.1.25 Surface Finishes Produced Without Formwork
Screeded Finish: The concrete shall be levelled and screeded to produce a uniform plain or ridged surface as required. No further work shall be applied to the surface unless it is a first stage for a Wood Float or Steel Trowel Finish.
Wood Float Finish: The Screeded Finish shall be wood floated under light pressure to eliminate surface irregularities.
Steel Trowel Finish: When the moisture film has disappeared and the concrete has hardened sufficiently to prevent laitance from being worked to the surface, the surface to the Wood Float Finish shall be steel-trowelled under firm pressure to produce a dense, smooth uniform surface free from trowel marks.
Where the type of finish is not given: hidden surfaces shall be ‘screeded finish’ and exposed surfaces “steel trowel” finish.
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4.1.26 Surface Finishes Produced With Formwork
Rough Finish: This finish shall be obtained by the use of moulds or properly designed forms of closely-jointed sawn boards. The surface shall be free from substantial voids, honeycombing or other large blemishes.
Fair Finish: This finish shall be obtained from forms designed to produce a hard smooth surface with true, clean arises. Only very minor surface blemishes shall be permitted and there shall be no staining or discolouration. Any projections shall be removed and the surface made good.
Fair Worked Finish: This finish shall be obtained by first producing a Fair Finish and then filling all surface blemishes with a fresh, specially prepared cement and fine aggregate paste whilst the concrete is still green where possible. After the concrete has been properly cured, the faces shall be rubbed down, if required, to produce a smooth and even surface. If the surface is to be exposed in the final work, every effort shall be made to match the colour of the concrete.
The following standard of concrete finish shall be achieved:
Type of Surface FinishExternal vertical surfaces below ground Rough Finish
External horizontal surfaces below ground Rough Finish
Internal vertical surfaces Fair Finish
Slab soffits Fair Finish
All other vertical, horizontal and sloping surfaces Fair Finish
4.1.27 High Strength Concrete Topping
High strength concrete topping (granolithic finish) shall be provided, laid and wood float finished unless otherwise specified.
4.1.28 Tie Bolts for Formwork
Only tie bolts which avoid embedding any metal parts permanently within 50mm of the concrete surface shall be permitted. Voids remaining after the removal of all or part of each tie bolt shall be filled flush with the surrounding concrete using a freshly prepared cement and fine aggregate paste.
In the case of structures designed to retain an aqueous liquid, the Contractor shall ensure that the tie bolts shall have a pre-formed water stop.
4.1.29 Tolerance for Concrete Surfaces
The “very minor surface blemishes” permitted in the Fair Finish are defined as follows:-
The surface blemish must not penetrate more than 5mm into the concrete. The area of an isolated surface blemish must not be more than 0.01m2.
The total area of all the surface blemishes on the face of a particular pour must not be more than 2% of the total surface area of that pour.
No work in connection with the making good of new concrete surfaces shall be carried out until the Engineer has examined the surfaces in question and has given his consent to the proposed preparation and treatment.
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All surfaces to be made good shall be carefully prepared in order to provide a good bonding surface to the satisfaction of the Engineer. This preparatory work may involve cutting out, chipping, wire brushing, air blowing and drying to remove curing membranes etc.
Unless otherwise directed or approved by the Engineer the following methods shall be used:
All making good of water retaining concrete surfaces shall be carried out using an epoxy resin in accordance with the manufacturer’s instructions.
This material is a two part mortar pack which shall be mixed and applied strictly in accordance with the manufacturer’s instructions.
All making good of non-water retaining concrete surfaces shall be carried out with a cement/sand mortar and PVA-based adhesive in accordance with the manufacturer’s instructions.
The mortar mix proportions, use of adhesives and method of application shall be as to the satisfaction of the Engineer. It should be noted that in certain instances the Contractor may have to experiment with trial mixes to achieve a colour/texture match to the original surfaces that is acceptable to the Engineer.
The setting out tolerance for the position of structures shall be ±20mm.
Unless otherwise stated, or directed by the requirements of mechanical equipment, concrete surfaces in the final work shall not vary by more than the permissible amounts shown in the table below:
Table 4.31.1 – Tolerance for Concrete Surfaces
Type of Structure
Dimension Measured
Tolerance (mm)
Finish Produced With Formwork Finish Produced Without Formwork
Fair Fairworked Screeded Wood/Steelfloat
Buried Concrete Position AlignmentHeight up to 5mThicknessStraightness in 5mPlumb per m (Limit) Step Displacement
±25±15±25±10±15
20 (30)10
-------
±25±15±15±10±10
-10
-------
Ordinary Exposed Concrete
Position AlignmentHeight up to 5mThicknessStraightness in 5mPlumb per m (Limit) Step Displacement
-------
±20±10±10±5±10
3 (15)3
±10±10
-±5±10
-5
±10±3-
±5±10
-0
** Exposed Concrete (where mechanical plant is to be installed), Pre-cast Concrete Screeds
Position AlignmentHeight up to 5mThicknessStraightness in 5mPlumb per m (Limit) Step Displacement
-------
±5±3±5±5±3
3 (5)0
±3±3-
±5±5-3
±3±2-
±5±3-0
Measuring Devices (Weirs, etc)
Position AlignmentStraightness in 1mPlumb per m (Limit) Step Displacement
-----
±2±2±2
2 (2)0
-----
±2±2±2-0
Notes: ** This group is intended to be used where mechanical plant bears directly on the concrete. Where plant is mounted on grouted beds, shims and the like, work shall be constructed within the tolerances specified for Ordinary Exposed Concrete.
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Definitions of Dimensions Measured
Position - relation to position, in line, slope or level shown on the drawings.
Alignment - relation to any previously placed coincident and adjacent part of the structure.
Height - vertical dimension
Thickness - dimension between opposite faces dimensioned on the drawings.
Straightness - departure from a 5m template which may be straight or curved as appropriate, placed horizontally and/or vertically.
Plumb - true vertically.
Step Displacement - abrupt displacement of any exposed face or surface.
No relaxation in the required concrete cover to reinforcement shall be implied or permitted.
Finished surfaces shall have no abrupt irregularities.
In case of failure to comply with the required tolerances in areas determined to be visually or functionally non-critical, the Contractor may submit for approval details of remedial surface works as an alternative to removal and proper re-execution.
In case of failure to comply with the required tolerances in visually or functionally critical areas, out of tolerance work shall be removed and properly re-executed as provided in the Contract.
4.1.30 Marking of Precast Concrete Components
Where appropriate, indelible identification and orientation marks shall be put on all precast concrete components in such a position that the marks shall not show or be exposed in the finished work.
4.1.31 Concrete Testing
Testing may be carried out to any recognised appropriate set of standards, provided that consistency in the application of the standards is ensured. The limits of acceptance shall, however, be as defined herein relative to the specified standard.
Sampling and testing shall be in accordance with the relevant sections of EN 12350, STAS 1275-88, STAS 6652/ I -82 or the following relevant ISO, or as directed by the Engineer.
ISO 1920 - dimensions, tolerances and applicability of test specimens;
ISO 2736-1 - test specimens part 1 - sampling of fresh concrete;
ISO 2736-2 - test specimens part 2 - making and curing of test specimens for strength tests.
Romanian test requirements
TestNo of Samples
Class Bc 25 Class Bc 15 Class Bc 7.5Workability(slump test) Every batch Every batch Not required
Compressive Strength1 sample every 10
batches1 sample every 10
batches1 sample every 50
batches
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For each sample of concrete three 150 mm cubes shall be prepared and cured. One shall be crushed at 7 days and two at 28 days.
Ready mixed concrete shall be tested by the supplier as part of his quality control. Copies of such test results shall be made available to the Engineer on request. Where concrete is mixed on site, or where records are not available from the supplier, additional testing will be required on site as directed by the Engineer.
The Contractor shall be responsible for manufacturing, transporting, storing, curing and testing of concrete cubes required to ensure compliance of mixes as specified.
4.1.32 Sampling Cubes
The rate of concrete sampling shall be as follows. At least one sample of concrete shall be taken from each grade and type of structural concrete each day.
Type of structureSample to represent a volume
of (m 3)Critical structureIntermediate structureHeavy concrete construction
1050100
From each sample two cubes shall be made for testing at 28 days and one for testing at 7 days for control purposes. The 28 day test result shall be the mean of two cubes.
The Contractor shall, for each cube taken, keep and make available to the Engineer detailed records showing:
Cube reference number
Location and batch from which the sample has been taken for the preparation of the cube
Date of preparation
Weather conditions at time of sampling
Date of testing
Age of concrete at time of test
Compressive Strength in N/mm2
4.1.33 Cube Strength Results
The results of the tests done on the samples collected on site shall observe the conditions imposed by NE012-99.
In order to establish the class of concrete, any test result of cube strength shall be at least equal to the minimum permitted strength given below.
Type Class Permitted Rmin
B50 C2.8/3.5 (Bc 3.5) 30B200 C12/15 (Bc 15) 135B250 C16/20 (Bc20) 180
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The assessment of concrete compliance shall be carried out in accordance with the following requirements:
a) Any one strength shall be over the required strength minus the following:
2.0 N/mm2 (required strength = 7.5 to 15.0 N/mm2)
3.0 N/mm2 (required strength = 20.0 N/mm2 or more), and
b) An average of any 2, 3 or 4 consecutive test results shall be over the required strength plus the following:
Required Strength N/mm2No of consecutive tests
2 3 4
7.5 – 15.0 --- 10 20
20.0 or more 10 20 30
If the specified characteristic strength has not been achieved or individual results do not comply with the above conditions then any of the following actions may be instructed:
a) Changing the mix;
b) Improving quality control;
c) Cutting and testing cores from placed concrete;
d) Load testing relevant structural units;
e) Non-destructive testing of placed concrete;
f) Cutting-out and replacing defective concrete.
4.1.34 Other Tests
Compaction factor (EN 12350-5, ISO 4111), slump (EN 12350-2, ISO 4109), Vebe (EN 12350-3, ISO 4110) or other workability tests shall be carried out as required during concreting of permanent works to control workability at the batching plant and at the site of the pour. The degree of workability shall be as for the trial mixes.
4.1.35 Contamination
Concrete shall be protected from contamination by sea or brackish water, oil, fuel and other deleterious materials for a minimum period of 30 days after placing.
4.1.36 Protection of Joints
Rebates formed to receive sealant and the surfaces of construction joints shall be protected from curing compound by wet hessian to ensure proper curing of the joint surface and adjacent concrete. The protection shall remain in place until the joint surface is sealed.
4.1.37 Specimen Panels of Concrete
If required, the Contractor shall produce specimen panels of finished concrete for approval.
4.1.38 Benching
Where benching is used the minimum thickness will be 40mm.
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5 BUILDING WORKS
Unless otherwise specified, all building works in this section shall be carried out in accordance with best international practices (or equivalent local practices), local building regulations (where relevant), bylaws, or in accordance with manufacturer's recommendations.
5.1 BRICKWORK AND BLOCKWORK, GENERAL
Construction in masonry shall be according to the provisions contained in the STAS standard 10109/1 –82.
The moisture content of bricks shall be adjusted so that excessive suction is not exerted on the mortar.
Bricks in each course shall break joint correctly with the bricks below. The courses shall be laid parallel with joints of uniform thickness and shall be kept straight or regularly curved as required. Brickwork shall be gauged to rise 300 mm in 4 courses.
Vertical joints shall be in alignment as required by the bond and shall have an average thickness of 10 mm. Bricks forming reveals, internal or external angles, shall be selected for squareness and built plumb. Bricks with single frogs shall be laid frog upwards.
Brickwork and blockwork shall rise uniformly; corners and other advanced work shall be raked back and not raised above the general level more than 1 m. No brickwork shall be carried up higher than 1.5 m in one day. No bats or broken bricks shall be incorporated in the work unless essential for bond. Where cut blocks are required, all cutting shall be carried out using a mechanical disk cutter.
Completed brickwork and blockwork shall be protected at all times from scaffold splash, mortar droppings, and grout leakage from suspended slabs and other harmful effects. Brickwork and blockwork shall be allowed to set hard before cutting and chasing is carried out.
Mortar for engineering brickwork shall be Class M50Z or as otherwise agreed with the Engineer.
Testing of classes of mortar shall be according to STAS 2634-80. The minimum compressive strength at 28 days of M 50Z according to STAS 1030-84 is of 5 N/mm2.
The composition of mortar that can be used without preliminary trials in the case of using natural sands (according to STAS 1667-76) is shown below.
Mark of mortar
Type of mortar
Materials for one m3 of mortar
Cement Pa 35 Paste of lime Sand
M50 Z Cement-lime(kg)230
(m3)0,09
(kg)115
(m3)1,18
(kg)1600
The bond shall be to suit local requirements.
The Contractor shall allow for preparing a 1 metre square sample panel of facing brickwork. The panels shall be completed and the mortar allowed to cure for two days minimum before being presented for approval.
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a) Approval to the sample panels must be obtained from the Engineer before brickwork is commenced.
b) The final approved sample panels will be used as a quality guide for the facing work and any facing work which does not meet the standard of the approved panels will be condemned. The sample panels shall be sited where they can be protected, and shall be removed only after the completed facework has been approved.
c) Should the sample panel be insufficient to achieve a satisfactory standard of workmanship, then additional panels may be required to achieve an approval.
5.2 BRICKWORK AND BLOCKWORK, JOINTING AND POINTING
Bricks and blocks shall be laid in mortar properly bedded and jointed and all joints filled with mortar at every course.
Where the surface of walling does not provide an adequate key, the joints on faces of walls to be plastered shall be raked out 12 mm deep.
Brickwork or blockwork for internal surfaces which are not to be rendered or plastered shall be finished flush.
For both brickwork and blockwork, the Contractor shall build in vertical contraction/expansion joints in accordance with the requirements of acceptable international (or equivalent local) standards or practices.
5.2.1 Tolerances in masonry works
The following checks shall be carried out on the constructed walls:
Thickness of the unplastered walls shall be the average of 3 measurements per wall. The tolerance for 250mm block walls shall be ± 8 mm and ± 6mm for brickwork.
Thickness of vertical and horizontal joints shall be done by establishing of an average thickness of joint measured horizontally and vertically. The tolerances in the thickness of the joints shall be of ± 2 mm for both horizontal and vertical joints.
The deviation from the horizontal of the top surface of each masonry row shall be maximum 2 mm/m and 15 mm over the entire length of the wall.
The deviation from vertical shall be 3 mm/m and at most 6 mm on the entire height of the wall.
For dimensions of rooms and of the position and sizes of doors, windows, etc the deviations shall not be more than 10 mm.
Plastering shall not start until the brick or block walls have been approved by the Engineer.
5.3 WATERPROOFING FOR TERRACES/FLAT ROOFS
Concrete roofs shall be provided with polystyrene thermal insulation and waterproofing materials and allow for surface water drainage.
Waterproofing shall be as follows:
Priming with bitumen solution, at least 300 g/m2
Vapour barrier from perforated bituminised felt IBP 1200, IBP 1100 (as required)
Vapour barrier – polyethylene foil 0.8 mm thick.
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Bituminised membrane, 4 mm thick reinforced with polyester felt.
Bituminised membrane reinforced with polyester felt with slate chippings 3 mm thick for protection.
Waterproofing works shall comply with Norm C 112-1986:
Storage of the materials shall be close to the work and be clean and dry.
Bituminised sheets, bitumen and ancillary materials shall have quality certificates and correspond to the technical specifications
Hot applied waterproofing works shall be done at temperature above 5°C and in dry conditions.
For the works done during cold weather “Norm for execution during cold weather of the construction and installation works C16-84" shall apply
Waterproofing material fitted around pipes and other obstructions shall be done in accordance with the manufacturer’s instructions to achieve a sound waterproof structure.
External drains under the fascia board shall be sealed with bitumen mastic and an additional layer of bituminised felt 30-50cm wide.
5.4 THERMAL INSULATION OF TERRACES/FLAT ROOFS
The thermal insulating layer shall 6cm thick in agreement with the specifications of STAS 6472/3-89 unless otherwise indicated and shall be from mineral wool slabs 6 cm thick and density, G200.
The general recommendations regarding the execution of thermal insulation works are provided by the “Norm for designing and execution of the thermal insulation works for buildings C107-1982”.
In case of the possibility of rain during the laying of the insulation, the surface of the insulating layer shall be temporarily protected until the work can commence in dry conditions.
Protection of insulation on terraces and non-accessible roofs shall be done with heat welded membranes.
Inspection of the works
Insulation works shall be checked as they are executed and a report made showing the following:
Quality of the support – rigidity, adherence, evenness, humidity;
Quality of the waterproofing materials;
Quality of priming and correct bonding of each layer
Fixing around obstructions and joints.
Visual checks shall include:
Uniformity and continuity of bonding with bitumen mastic
Drainage slopes – no ponding
Connection where the material is pierced e.g. pipes
Protection measures
Vertical waterproofing
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Where directed for surfaces larger than 20 m² a waterproofness and drainage test shall be carried out by flooding the roof with water.
During this test the ceilings shall not show moisture after 72 hours of maintaining the test.
All the materials used must correspond to the quality requirements from the current standards and will be accompanied by quality certificates and technical agreements.
5.5 DAMP PROOF COURSE
Damp proof courses and cavity trays shall be pitch polymer material, and preformed cloaks and trays shall be utilised wherever possible.
The minimum overlap at joints shall be 100 mm.
Vertical damp proof courses shall be in one piece. The leading edge of any damp proof course shall be kept flush with the exposed face of the brickwork and shall extend 25 mm minimum beyond any masonry cavity closure, into the cavity.
Vertical damp proof courses at openings shall be lapped behind any cavity tray over an opening, and over any horizontal damp proof course at sills.
Damp proof trays shall extend 150 mm beyond the ends of lintels and shall have stop ends formed to prevent drainage into the cavity.
5.6 BONDING TO CONCRETE
Where brickwork or blockwork is to be bonded to concrete, this shall be achieved by means of metal ties evenly placed at 3 per square metre , and brickwork and blockwork shall be brought up subsequent to the concrete.
Masonry facing shall be bonded to new and existing concrete surfaces using cast-in or grout-in anchors in accordance with the specification or to the approval of the Engineer.
Grout-in ties shall be installed and grouted in using an approved strong mixture not less than two days before laying masonry around them.
5.7 CENTERING AND LAGGING
Centering and lagging used for the construction of brickwork and blockwork shall remain in place for such time as is necessary for the brickwork and blockwork to develop sufficient strength to prevent sagging or cracking of joints.
5.8 BRICKLAYING AND BLOCKLAYING IN COLD WEATHER
Materials used in bricklaying and blocklaying shall be frost free and no bricks or blocks shall be laid when the ambient temperature is below 3 deg. C, unless special precautions are taken. The Contractor shall ensure that any additive used in the mortar does not cause a variation in the colour of the joints. Completed work shall be protected adequately during cold weather.
Brickwork/blockwork construction during winter conditions shall be accordance with local regulations and practices where these differ from this specification.
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During bricklaying/blocklaying, contemporary weather records shall be kept including maximum and minimum temperatures.
5.9 PREPARATION FOR PLASTERING
Unless a bonding agent is used, concrete ceilings, ceiling beams, columns and stanchions shall be dubbed out as necessary before plastering is commenced and the mix used for dubbing shall be similar to that used for first undercoating. The surface of the in-situ concrete shall be cleaned of dust, loose particles and other matter. Surfaces shall be wetted immediately before start of plastering.
Angles between walls and ceilings, vertical angles and joints between dissimilar materials shall be reinforced with 90 mm wide scrim set in plaster and trowelled flat. All joints between plasterboards shall be similarly treated.
Expanded metal angle beads shall be provided at all external corners.
5.10 FIXING OF PLASTERBOARD
The Contractor shall propose the type of light partition required to achieve the objectives shown on the drawings. Installation shall be in accordance with the manufacturer’s specifications, which shall be the subject of approval along with the proposed partitioning system.
Plasterboard panels shall be 25-30kg/m2. Assembling system shall be with metallic mounting elements and structure and panels shall be easily disassembled.
Plasterboard for ceilings shall be nailed to the support at 150 mm centres with 40 mm sheradised plasterboard nails and fastened so that the joints are staggered. Noggins or other fixing surface shall be provided as necessary to ensure that edges of plasterboard are secured adequately. Ends of sheets shall be butted tightly and edges left with a gap not exceeding 5 mm.
Where sheeting has been cut, nails shall not be less than 18 mm from cut edges. Nails shall be driven well home with heads slightly below the surface but shall not break the paper.
Plasterboard shall be set out with bonded joints with sealed edges across the supports, and securely fixed at every support. A space of 5 mm shall be left between each board and between boards and abutments and, where the boards are subsequently to be plastered, the joints shall be covered with jute scrim, 100 mm wide, set in plaster.
Support shall be provided at the perimeter of all boards, and plasterboard shall be fixed with the paper covered edges at right angles to the main supports.
Plasterboard ceilings shall be finished with a plaster skim coat.
5.11 PLASTERING
Plastering shall normally be applied in 2 coats in accordance with the manufacturer's instructions and batches shall be used as soon as possible after water has been added.
Interior wet plastering shall comply with the following the pattern set by a standard test sample:
For the first course:
mechanized application of the mortar 12-15 mm
manual application 9 mm
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For the top course – manually applied 7-8 mm
Surface Preparation
Prior to plastering the surfaces shall left for a while to avoid settlement or contraction.
The mortar should have hardened in the joints and the surfaces should be dry in order not to let moisture affect the adherence of the plaster.
All construction and installation works, services etc shall be finished that would otherwise damage the finished plaster.
The support surfaces shall be clean. Expanded metal netting must be well-stretched and tied using zinc plated ties, according to good working practice.
The joints of the brick masonry shall be cleaned and any smooth concrete surfaces must be roughened to provide a key for the plaster.
5.11.1 Plastering in Cold Weather
When the ambient temperature is 5 deg. C or less, the portion of the Works to be plastered shall be completely enclosed. The ambient temperature shall be raised and maintained above 5 deg. C until completion of plastering and hydration.
5.12 CONCRETE FLOOR FINISHES
Concrete floors shall be finished as specified in the Contract.
Minimum thickness of any cement or concrete screed shall be in accordance with the following:-
a) laid monolithically with base slab 10 mm;
b) laid on and fully bonded to a set and hardened base slab 25 mm;
c) laid on a separating membrane 75 mm.
All concrete floor finishes shall have a fall which will enable the floor to be washed down and drain to a suitable outlet.
5.13 SHEET VINYL FLOORS
Before the ordering and delivery of any materials on site the Contractor shall submit samples for approval to the engineer for his approval.
Materials shall be transported, stored and installed in accordance with the manufacturer recommendations.
Floor screeds
Floor screeds shall be a level cement mortar M100 prepared with sand 0-7mm.
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Laying the floor cover
Where the flooring material is to be laid the temperature of the material and room shall be at least +16°C and a relative air moisture of max. 65% for a period of 48 hours before laying.
These conditions shall be maintained during the laying and at least 30 days after.
The cement mortar or concrete base in the case when the sheeting is glued with adhesive shall be dry.
If the laying surface requires repair of any kind the Contractor, at his cost, shall propose to the engineer a suitable mortar mix or commercial epoxy for its repair.
Gluing of the sheeting
The sheet shall be glued, finished and cured following the manufacturer’s requirements.
Fixing of skirting boards
The sheet shall be fixed to skirting boards according to the manufacturer’s requirements.
5.14 STONEWARE FLOORS
Laying stoneware floors
Mortar for bedding shall contain between 300-350kg of cement for 1m3 of sand and shall be laid 25 to 30mm thick. Mortar shall consist of ordinary cement type Pa 35, sand with the grains 0…3mm mixing one part cement with 3.5-4 parts sand. Fast drying cement (P40 etc.) shall not be utilized. The water-cement factor will not exceed 0.5.
Stoneware tiles shall be immersed in water for 2-3 hours.
Joints shall be at least 3mm wide.
Tiling shall be carried out in accordance with good practice to the approval of the Engineer.
Finishing of the floor
Stoneware tiles shall not be polished but wiped with a moist cloth.
Expansion joints at 30m2 or 6m, shall be fitted unless otherwise indicated.
5.15 POLISHED CEMENT AND MOSAIC FLOORS
Laying of polished cement and mosaic floors
Polished cement floors shall be from a layer of cement mortar. The cement quantity will be 300kg/m3 of polished cement.
The mosaic floor shall have two layers:
Cement mortar coping 30 – 50 mm thick;
Cover from cast mosaic about 15 mm thick.
The polished cement and mosaic cover shall be a cement mortar using 400kg of cement per m3 of sand 3mm.
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Adequate curing of the floor shall be maintained.
Finishing of the mosaic floor shall be by grinding and polishing. Grinding shall take place 4 – 6 days from the pouring by grinding machine.
5.16 CERAMIC AND QUARRY TILED FLOORS
Ceramic tiles and flooring shall be group B1, according to the norms UNI EN 87 and UNI EN 176 according to the following table:
Baking temperature 1200 – 1250°CH2O absorption UNI EN 99Resistance to flexion UNI EN 100Superficial toughness UNI EN 101Resistance to chemical agents UNI EN 106Resistance to frost UNI EN 202Resistance to temperature variation UNI EN 104Stability of the colours at light and UV radiation DIN 51094Resistance to deep abrasion UNI EN 102
Laying of tiles shall be in accordance with manufacturer’s specifications and good practice, all of which shall be demonstrated to the engineer by carrying out representative samples.
Any section of work rejected by the Engineer shall be made good at the expense of the Contractor.
5.17 EXTERNAL RENDERING
External rendering shall be in 2 layers using a cement/lime mortar with approved admixtures for the first layer. Baumit type or similar mortar shall be used for the top layer.
The supporting surface shall be dry, unfrozen and free from dust and capable of supporting the applied mortar. All joints and holes shall be filled with lime cement mortar to achieve a level surface. All surfaces where the mortar is to be applied shall then be prepared with a priming layer and a reinforcing glass fibre mesh secured to the structure.
Total thickness shall be not less than 20 mm applied in 2 layers. The mix for the first layer shall be Class MPA 35 mortar and shall be applied, levelled, scored and left to dry for not less than 10 days before applying the top layer. The air temperature shall not be less than +5 degrees C during the works and drying period. Direct heating of the mortar is not allowed.
The surface shall be cured by keeping damp for not less than 2 days after completion.
Mortar shall be machine applied in accordance with the specific requirements of the Contract.
The top layer shall be Baumit mineral render or similar applied strictly in accordance with the manufacturer’s requirements. Depending on the time between applications of the layers a primer may be required on the lower layer if deemed necessary by the Engineer.
5.18 CARPENTRY AND JOINERY
Wherever possible, cutting and shaping of all timber shall be completed before preservative treatment is carried out. Where any cutting or shaping has to be carried out after treatment, the cut and worked
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surfaces shall be given 2 coats of preservative. After treatment, timber shall be thoroughly dried out before use.
The whole of the joinery shall be cut and framed together as soon as possible after the commencement of work. Except where work is described in the Contract as being to finished sizes, 3 mm shall be allowed for each wrot face. Frames, casings and other joinery fittings shall be secured to hardwood fixing slips built in for the purpose. Where hardwood fixing slips have not been provided, receiving surfaces shall be plugged with hardwood plugs or approved proprietary plugs.
Manufactured units to be painted shall be primed at the place of manufacture.
5.19 ROOFS
All roof timbers in trussed rafters shall be pre-pressure treated.
Thermal insulation to the roof shall be minimum 150 mm mineral quilt between joists laid on top of plaster board ceilings.
5.20 TIMBER FLOORS
Floor joists shall either be built into brickwork or blockwork, or held in galvanised steel joist hangers, and shall be trimmed as described in the Contract or as directed by the Engineer. Bridging shall be spaced every 1.8 m apart and shall be 50 mm thick to the full depth of the joists or 38 mm by 50 mm herringbone strutting.
Boarding shall be cramped up and nailed with cut flooring nails. Trimmed openings shall have mitred borders 75 mm in width.
Moisture content of the timber at the time of erection shall not be more than 18%.
Each board shall either be nailed with two nails or secret nailed to each joist.
A gap of 10 mm is to be left away from external elevation brickwork.
5.21 DOOR FRAMES
Door frames shall be fitted into prepared openings, drilled and plugged at 3 points per jamb and shall have 100 mm by 12 mm diameter galvanised steel dowels to posts let into flooring and bedded in non-shrink or epoxy grout.
The joint between external door frames and adjacent walls shall be continuously pointed with gun applied butyl or other approved non-setting mastic.
5.22 ROOF TILING
Where roof tiles are laid on a concrete fill the surface shall be swept and cleaned of all waste materials and shall be thoroughly wetted. A layer of slurry in neat cement and water shall be applied to the area to be paved prior to the laying of the bed. This slurry shall be brushed into the surface immediately before laying the cement bed. The tiles shall be thoroughly soaked in clean water before laying.
Tiles shall be laid with continuous joints and bedded in a cement and sand ( 1 : 6 ) screed or backing not less than 30 mm thick and pointed or grouted with cement slurry to match the tiles. Tiles shall be accurately cut and fitted to all doors, thresholds, wall openings, projections, etc. The finished floor shall
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be perfectly true, level or to the falls specified and cleaned off on completion of the work to the satisfaction of the Engineer.
After the tiles have been laid, the floor shall be covered immediately to give complete protection from dirt and damage during all subsequent stages of the work.
The Contractor will be required at his own expense to remove any tiles which have been stained or damaged before completion of the work and replace them with new ones.
5.23 BITUMEN FELT ROOFING
Unless otherwise specified bitumen felt roofing shall be applied to flat concrete roofs. The bitumen felt roofing shall consist of two layers comprising one layer fine granule surfaced bitumen glass fibre felt and one layer of fine granule surfaced bitumen felt.
The first layer is a bitumen coated glass base felt type 3B complying with CP 144:Part 3. This layer shall be continuously bonded to the primed cement and sand screed in hot bitumen. The nominal mass shall be 18 kg per 10 sq.m exclusive for wrapping or accessories.
Then a layer of bitumen coating shall be applied before the second layer of bitumen felt is placed.
The second top layer shall be bitumen saturated and coated fibre base felt type 1B which shall be surfaced with a bitumen dressing compound and mineral aggregate as described in CP 144:Part 3. The nominal mass shall be 14 kg per 10 m5 exclusive for wrapping or accessories.
All laps shall be placed breaking joint and minimum 50 mm wide. All necessary upstands, flashings, skirtings, etc. shall be provided. All exposed felt at upstands and gutters shall be painted with reflective aluminium paint.
Down spout channel shall be of prefabricated reinforced concrete made in size and dimension shown in the drawing, placed in position and fixed into parapet opening in slope using water proof mortar and sealed with mastic, lined with water proof bituminous flashing.
The whole water proofing shall be guaranteed up to 5 years against any leakage.
5.24 PLUMBING
Internal plumbing shall be installed in accordance with the Particular Specification to suit local practices and standards.
Isolation valves shall be provided to hot and cold water services for each major item served.
All pipework shall be rigidly supported on strong purpose-made brackets secured to the building structure. All pipework shall have adequate gradient for venting and draining with due allowance for movement due to expansion and contraction. Drain valves shall be provided to all system pipework to allow full draining down of the system. All pipework shall be insulated, unless directed otherwise.
5.25 OPENINGS IN WALLS, FLOORS, AND CEILINGS
The Contractor shall box out and/or cut openings through walls, floors and ceilings for the passage of pipes and cables and, where described in the Contract, shall provide and fix in position approved tube sleeves cut off flush with the finished surface. All openings shall be sealed on completion to prevent the passage of toxic or explosive gases.
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5.26 TOLERANCES FOR BUILDING WORKS
Tolerance for building works, except where otherwise described in the Contract, shall not exceed the permissible deviations from levels and dimensions accepted as complying with acceptable international (or equivalent local) standards and practices.
5.27 IRONMONGERY
Details of ironmongery are given in the Particular Specification.
All moving parts of joinery components are to be fixed with equal tolerance spaces all round. Hinges, etc., are to be fitted in perfect alignment, locks and fastenings are to engage properly in their striking plates or sockets without clatter. Screws for fixing ironmongery shall be of the same metal as the hardware. On completion all joinery shall be adjusted and ironmongery oiled and the whole shall be in perfect working order. Removable ironmongery, except hinges, shall be removed for painting and refitted prior to the final coat of paint or on completion as ordered by the Engineer.
Locks are to be fixed where shown in the Drawings or as directed by the Engineer. All external door locks shall have three keys, and all internal locks two keys. All locks and moving parts are to be oiled and left in perfect working order and all keys shall be properly marked and labelled and delivered up to the Engineer as required. All timber doors shall be fitted with an approved pattern of combined mortice lock and latch complete with aluminium lever handles. In addition double doors shall have barrel bolts fitted top and bottom to one leaf.
All locks, handles, latches and other similar ironmongery shall be subject to the approval of the Engineer.
5.28 BUILT-IN ARTICLES
Joints for flashings in brickwork, blockwork and masonry shall be raked out to a minimum depth of 25 mm as work proceeds and pointed up after flashings have been fitted.
Articles to be fixed in brickwork, blockwork and masonry shall be built in as work proceeds.
Where this is impracticable the Contractor shall use performed profiles to form pockets of the required size and shape to allow the articles to be subsequently built in.
All pipes shall be fixed securely in place before masonry is laid.
Brickwork, blockwork and masonry shall be built around pipes as neatly as possible, making joints and beds coincident with the pipes wherever practicable. Individual pieces shall be shaped to fit around the pipes where possible without undue damage and the areas of exposed mortar around the pipes shall be kept to a minimum.
5.29 GUTTERS AND DOWNPIPES
Unless otherwise specified by this Contract or by local building regulations, guttering shall be fixed to a building board fascia fixed to rafters projecting to allow a ventilation gap, equal to 25 mm continuous around perimeter of eaves, protected internally by a proprietary eaves ventilator.
5.30 EXTERNAL DOORS
Unless specified otherwise, doors to mess buildings and offices shall open inwards and all other doors shall open outwards.
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Doors for installation/removal of control panels shall have an overall clear opening height of 2500 mm unless detailed otherwise.
5.31 INTERNAL DOORS
Where appropriate all doors shall incorporate suitable softwood blockings for all ironmongery, locks, closers, etc.
All internal doors shall be finished with a primer, undercoat and gloss paint system finish.
5.32 ALUMINIUM DOORS AND WINDOWS
Aluminium doors and windows shall be from profiles of extruded anodised aluminium 6063.
External frames shall be thermally insulated ensuring a thermal break.
Glass shall be panels 4 + 12 + 6mm (colourless glass) with central washer (neoprene) and drainage. Heat loss shall not exceed 1.6W/m2 °C.
For the execution of the aluminium works:
The aluminium profiles shall be cut at 45°;
The glass panel shall be maintained in the correct vertical and horizontal position with special clamp bars. The mounting of the glass shall have a space between the frame to compensate for the elastic deforming due to temperature variations; in the lower and lateral part 4mm and in the upper part 5mm. To avoid vibrations rubber plugs between the glass and the frame shall be used.
Sealing shall be according to class E4 (no water infiltrating at an external pressure of 500 Pa and 25 Litres/minute/m.). Washers and mastics must be compatible with the aluminium frames.
Aluminium shall have all ancillaries and closing/opening mechanisms. In the case of doors the handling mechanism shall allow for the installation of locks and control devices.
All the assembling ancillaries (doorpost, long bolts) shall be galvanized or cadmium coated.
5.33 PAINTING
Internal painting shall be in accordance with Norm C 3-1976.
All emulsions, paints, stains, etc., shall be obtained from manufacturer(s) to be approved by the Engineer prior to commencement of the particular work.
The paints shall be used exactly as received from the manufacturers and under no circumstances will the addition of thinners, driers, or other material be permitted.
Filler for woodwork shall be an approved internal or external quality leadless oil filler, according to location.
Sizes, primers and sealers shall be of an approved proprietary type to suit the surface being sealed.
All floors, fittings, etc., and surfaces which are not to be painted shall be properly covered and protected during the progress of the painting work.
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The final colour of the walls and ceilings shall be in accordance with the agreed colour scheme for the Contract and 600 mm x 300 mm sample boards shall be prepared by the Contractor if required.
Storage of materials shall be in enclosed spaces, protected from moisture and provide safety against fire.
The temperature of the store shall be between 7°C and 20°C. During storage the packing shall be perfectly sealed to avoid deterioration of the paint.
Painting shall only be done after:
Finishing of the execution of the electrical and sanitary installations;
Testing of the installations;
Assembling of the carpentry, except latches and escutcheons;
Execution of the cold floors, including polishing;
Preparation of the areas to be painted;
Priming and undercoats shall be according to the manufacturer’s recommendations.
External painting works shall only be started after the completion of any other works that may be damaged by the paintwork.
Finishing works for the walls and ceilings shall start at a temperature of at least 5°C. These working conditions are maintained during the execution of the works and at least 8 hours after the execution of water soluble paint or 15 days for washable paint.
Before starting painting works surfaces shall be clean and dry. Painting may be by mechanical or manual spraying. Each paint layer shall be applied once the previous one is dry.
Forced drying shall be avoided.
The following checks shall be done:
Quality requirements for support surfaces and recording in the hidden works report;
Quality of the main materials used, according to manufacturing standards and norms;
Correctness of the execution.
Poor quality works shall be repaired or redone.
5.34 HANDRAILING
In the event that no specific design is substantiated, balusters shall have a maximum spacing of 1500 mm when fixed to concrete or 1800 mm when fixed to metalwork.
All handrails and balusters shall be designed to suit the stress limit of the material being considered and to a deflection limit of 25mm, when considering the Design Load.
Handrail loading shall be a minimum lateral load of 0.36 kN/m for regular two way traffic.
For all areas wider than 1000 mm and where the public has access or on escape routes, the lateral loading shall be taken as 0.74 kN/m for heavy duty use.
All flat base and side palm fixed balusters shall have as a minimum suitable two bolt fixings, to suit the design criteria and any close centre and close edge reductions that might apply to the bolt strength when
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fixing into the concrete. For two bolt fixings the minimum distance from the bolt centres to the edge of the concrete shall be 100 mm.
Rail joints shall be made using screwed nipple joints, or plug and pin joints if the rail cannot be turned during assembly. Ends of rails shall be properly capped or set into loose wall flanges fitted such that the tube can be fixed in the flange.
Infill panels to handrailing shall be galvanised wire mesh 10 gauge x 50 mm square with 6 mm rod frame as a minimum, secured to the inside of the lower rail and balusters with spun galvanised rail clips and bolts. The bottom section of the panel shall be strengthened with 6 mm x 25 mm galvanised mild steel bar, or attached to 50 mm long RSA brackets bolted to the walking level at maximum 500 mm centres.
Infill panels shall be provided between the walking level and intermediate rail on handrailing where the drop exceeds 2 m or where water is crossed, or less height where a risk assessment indicates a requirement e.g. where there is an added danger of falling into dangerous substances, moving unguarded machinery or fragile covers.
Kicker plates shall be provided. Kicker plates shall not be used in lieu of mesh infill panels. The minimum upstand shall be 100 mm and the minimum thickness 6 mm.
Removable sections of handrail shall be from solid galvanised steel bars. Chains may be used provided that they are permanently secured at one end.
There shall be a continuation of guarding at tops of ladders which shall be by pivoted bar or hinged gate of a self-closing type, shall open inwards and shall be lockable.
All designs submitted shall be substantiated by calculations proving the capabilities of baluster shanks, base plates, welds from shank to base plate, fixing bolts and handrail to withstand the design load considered at the pitch specified without exceeding the deflection limit.
5.35 SNAGGING WORK
The Contractor shall:
a) Make good all damage.
b) Remove all temporary markings, coverings, and protective wrappings unless otherwise instructed.
c) Clean all work thoroughly inside and out, removing all splashes, deposits, efflorescence, rubbish and surplus.
d) On painted surfaces, touch up minor faults in newly painted or repainted work, carefully matching colour and brushing out edges.
e) Repaint badly marked areas back to breaks or junctions.
f) Adjust, ease and lubricate moving parts or new works as necessary to ensure easy and efficient operation including doors, window, ironmongery, appliances and components.
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6 SANITARY INSTALLATION
6.1 MATERIALS
The materials used for executing the PSI and sanitary installations shall be galvanised pipe, screwed STAS 7656, and fittings of galvanised malleable cast iron or as described elsewhere in the Contract.
6.2 PLUMBING PIPING AND ACCESSORIES
6.2.1 Plumbing Piping Identification
6.2.1.1 Valve Identification
a) General Identification shall be required for all control and shut off valves except faucets and hose
bibs.
The identification tags shall be round or hexagonal, approximately 40mm size; solid plastic plate tie wire; permanently stamped or embossed with suitable name or number per approved schedule.
b) Coding System The Contractor shall develop and provide number/ name/ function code schedule or name
system schedule for all valves requiring tags.
The Contractor shall provide a complete listing for valves and accompanying code identifications.
The Contractor shall submit coding schedules for approval within 90 days following the time general material submittals are approved.
The system shall be approved by the Engineer prior to ordering or fabrication of tags.
6.2.1.2 Piping Identification
a) General Piping systems under this Section shall be identified using coloured stencilled legends or
pre-printed labels as specified, including flow direction arrows.
Piping work shall be cleaned and completely field painted prior to application of labels, etc.
Legend and flow arrows shall be applied at valve locations, at points where piping enters or leaves walls, partitions, bulkheads, cluster or piping or similar obstructions and at about 2 meter intervals on pipe runs.
Changes in locations and spacing may be made with the approval of the Engineer to meet specific conditions.
Wherever two or more pipes run parallel and close to each other printed legends and other marking shall be applied at the same relative location so as to be wither vertical or horizontal alignment as the case may be.
Paint: Enamel paint brushed on or sprayed from pressurized cans; in colour per schedule herein; uniform throughout and in hues as approved.
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Where pipe marking colours are not easily visible over background, such as brown on soil pipe, orange on copper pipe, or similar combinations, a neat white or aluminium coloured background shall be painted on the pipe before marking are applied.
6.2.1.3 Pipe Support Spacing Schedule
a) Steel Pipes: The maximum permissible support spacing for steel pipes and tubes shall be as follows:
Nominal Bore(mm)
Support SpacingHorizontal Runs
(m)Vertical Runs
(m)1219253238506575100125150
2.002.502.503.003.003.003.503.503.504.505.50
3.003.753.754.504.504.505.255.255.256.758.25
b) PVC Pipes: The maximum permissible support spacing for PVC pipe and tubes shall be as follows:
Nominal Support SpacingBore(mm)
Horizontal Runs (m)
Vertical Runs(m)
12-3850-6575-125150-200225-300
0.921.121.521.832.44
1.832.202.443.053.65
6.2.1.4 Pipe Hanger Sizes
a) General: Pipe hangers shall be specifically designed units for the intended purposes in accordance with the applicable and as approved by the Engineer.
b) Rods: Shall be of solid steel of the following sizes:
Diameter of Pipe Supported (mm) Minimum Rod Diameter (mm)75 and less100 to 125
150 and above
91316
c) Support Capacity of Hanger Support capacity of hanger shall not be less than five (5) times the combined full load of
pipe plus water.
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The above load capacity shall be applicable to all parts of the hanger including fastenings to structures and connections to pipe work.
The size of rods or connections shall be increased wherever it is necessary to meet the requirement stated above.
d) Multi-Pipe Supports Hanger rods supporting multi-pipes shall have a diameter of 16mm or more.
The individual supports shall not exceed 1200mm in width.
The spacing between consecutive hangers shall not exceed 2000mm.
e) Hanger Surface Finish: All parts of all hangers shall be hot-dip galvanized throughout regardless of where they shall be located or used.
Gaskets
a) Rubber Gaskets shall be durable, suitable for the pressure temperature and water quality of the works ad also for the water service as required.
b) Liquid Gaskets shall be made of a synthetic rubber compound specifically formulated for the intended service.
6.2.1.5 Sealing Tape
Sealing tape used for threaded connections shall be made of TEFLON or approved equal suitable for use at temperatures between –50ºC and +180ºC.
6.2.1.6 Adhesive
Adhesive material used for jointing polyvinyl chloride pipes shall be polyvinyl chloride resin solvent specifically formulated for use with the PVC pipe specified conforming to ASTM D 2564.
6.2.1.7 Pipe Sleeves and Escutcheons
a) General: Pipe sleeves shall be provided where pipes pass through concrete floors or walls; for sufficient size to allow for the required packing and sealant and free movements of pipe; including allowance for insulation where appropriate.
b) Floor Slabs or Wall below Ground
Permanent sleeves of galvanized steel pipe shall be installed.
The finish shall be flushed in walls and extend a minimum of 50mm above floor slabs.
The space between the pipe and the sleeve shall be sealed with oakum and mastic sealant and made positively watertight.
c) Sleeves Elsewhere
Pre-fabricated expandable type sleeves or field made sleeves of the size required shall be made of galvanized steel sheet not less than 0.7mm.
In concrete: The sleeve shall be removed following the removal of the formwork, and before installation of pipe work through the sleeve.
Through fire-rated construction: The sleeve shall be packed using approved incombustible packing and materials.
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d) Escutcheons
Escutcheons shall be required for pipes passing through floors, walls and ceiling at all interior spaces; whether the pipe is insulated or not.
Typical Sizes: Standard type split escutcheons with either spring or set screw clamping.
Over Sizes: Fabricated to the required sizes using sheet metal and properly secured.
Finish-Typical Sizes
Finishes for toilets, shower rooms, kitchens and other wet areas shall be polished chromium plated.
Elsewhere: shall be prime painted steel.
Finish-Over Sizes
Finishes for toilets, shower rooms, kitchens and other wet areas shall be stainless steel sheet metal; satin finish.
Elsewhere: Shall be primer painted galvanized sheet metal.
e) Pipe Penetration
Pipes passing through Fire Walls: The penetration space shall be filled using rock wool or other approved incombustible material.
Where penetration is required to be watertight: The penetration space shall be filled using suitable back-up material and sealed using approved sealant.
6.2.1.8 Valves and Strainers
All valves shall be selected according to the following schedule unless otherwise specified:
6.2.2 Water Meters and Other Accessories
a) Water Meter Water meters of nominal size 20mm to 40mm shall be constructed in accordance with the
Romanian Water Authority standards, AWWA C 700, ASTM Standard or equivalent can be used if approved by the Water Authority. They shall be of cast bronze, vane wheel, double jet type with strainers and direct reading water flow accumulator, with union coupling ends dry type indicating elements (magnetic or other).
Water meters of nominal size 50mm and above shall be constructed in accordance with Romanian Water Authority Standard, ASTM standard or AWWA C-700 or equivalent can be used if approved by the Authority. They shall be of cast iron body, vane wheel, direct stream type with strainer and direct reading water flow accumulator, flanged ends, with dry type indicating elements (magnetic or other).
b) Pressure Gauge and Compound Gauge Pressure gauges shall be of the Bourdon tube type complying with JIS B 7505, ANSI-B-
40.1, equivalent EU or Romanian Standard. Cases shall be of brass, with flange on the back face for panel mounting, enclosing a dial face of 100mm diameter.
Graduations, numerals and lettering on the dial face shall be black on white background. Calibration shall be in bar or kPa and shall be capable of indication to twice the normal working pressure of the system.
Accuracy of indication over the complete scale range shall be within +0.5%.
The pressure gauge shall be complete with a siphon tube and pressure gauge valve.
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c) Water Level Gauges Water level gauge of the sight glass shall be provided for each cold-water storage tanks.
The sight glass tube shall be 10mm side diameter and capable of withstanding 150% of highest working pressure.
Each sight glass tube shall be two (2) gauge shut off valves and metal guard.
6.3 PLUMBING EQUIPMENT
6.3.1 Cold Water Supply Pumps
a) Cold water supply unit shall consist of water pumps, pressure tank and its automatic control devices.
All water pumps shall be of the end suction centrifugal type.
The pump casing and back-plate shall be constructed of cast iron.
The impeller and internal fittings shall be constructed of bronze and soft-packed gland with a logging ring and a replaceable shaft sleeve.
The shaft shall be made of stainless steel on ball or roller bearing.
The pumps shall be directly coupled to a drip-proof class E motor suitable for operating at an electrical power supply of 230V, 3-phase, 60 Hertz.
The full load speed shall not exceed 1500 RPM. The rotating parts shall be thoroughly, dynamically and statically balanced.
The pressure tank shall be of prefabricated steel tank with diaphragm device having working pressure of 490 kPa (5.0kgf/cm2)
Automatic control devices shall be as shown on the Drawings as parallel/ alternate operation.
A complete pump unit shall comprise of but not limited to the following items:
- Pumps complete with casing, impeller, shaft, motor and base plate and rails.
- Supports, brackets, fixing and anchor bolts and nuts, screws and washers.
- Pipe fittings, flexible joints, unions, couplings, flanges and relevant nuts, bolts and washers.
- Anti-vibration mountings.
- Pressure tank unit with pressure relief valve, back-flow prevention valve and complete operation devices, switchgear and automatic control units.
- Suction and delivery stop valves.
- Delivery non-return valve.
- Air and drain cock.
- Delivery pressure gauge of range and dial diameter specified elsewhere in these Specifications with siphon tube and gauge valve.
- Vacuum gauge with siphon tube and gauge valve.
- Priming water funnel with cock.
- All elements shall be integrated into single unit, pumps, motors, control panel, pressure tank, pressure switch and etc. and shall be mounted on a common base.
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- Anchor bolts with washers and nuts.
b) Each pump set shall be capable of delivering not less than the water flow rate indicated against the design head. The Contractor shall submit for approval the characteristics curve of each pump offered.
6.3.2 Pipe Test and Sterilisation
6.3.2.1 General
After installation and before hydrostatic tests are carried out, the piping shall be thoroughly cleaned out.
Piping shall be disconnected from tanks, control valves and equipment before the piping is washed out.
All pipes and joints shall not be covered, painted and/ or insulated prior to satisfactory completion test.
6.3.2.2 Pressure Test for Cold Water Supply and Hot Water Pipe Work:
Following satisfactory pressure tests on the pipe work systems, operational tests shall be carried out on the system as a whole to establish that special valves, gauges, controls, fittings, equipment and plant are functioning correctly to the satisfaction of the Engineer.
The test pressure shall be applied by means of a manually operated test pump or, in the case of long main or mains of large diameter, by power driven test pump, which shall not be left unattended. In either case precautions shall be taken to ensure that the required pressure is not exceeded. Pressure gauges should be calibrated before the tests.
The Contractor shall provide all the test pumps and other equipment required to carry out the pressure tests.
The test pressure shall be two (1.5) times the maximum working pressure except where a pipe is manufactured from a material for which the relevant maximum test pressure shall be used.
The test pressure shall be maintained for at least sixty (60) minutes. At the end of this duration the pressure drop shall not exceed 5% of the test pressure.
6.3.2.3 Sterilization of Installation
All underground water mains and aboveground water distribution systems, cisterns, tank, calorifiers, pumps, etc. shall be thoroughly sterilized and flushed out after the completion of all tests and before being fully commissioned for turnover.
The sterilization procedures shall be carried out by the Contractor or Specialist employed by the Contractor to the approval of the Engineer and shall include but not limited to the following:
The tanks shall be scrubbed down and flushed out with water containing a solution of chloride or lime.
The tanks and pipes shall be then filled with water and sterilizing chemical containing chloride added mixing.
Sufficient chemical shall be sued to give the water a dose of 50 parts of chloride to one million parts of water (50 PPM).
When the tanks are full the supply shall be shut off. All the taps on the distributing pipe shall then be opened successively, working progressively away from the tanks.
Each tap shall be closed when the water discharged begins to smell of chlorine.
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The tanks shall then be topped up and the whole system whereupon a test shall be made for residual chlorine. If none is found, the sterilization shall not be carried out again.
Finally the tanks and pipes shall be thoroughly flushed out before any water is used for domestic purposes.
All tank openings, including tank drain and overflow pipe ends, shall have suitable provision for preventing the entry of vermin and insects to the requirements of the Local Authority.
6.3.2.4 Underground Drainage System
A site test shall be carried out on all drainage pipes before concrete hunching or surrounds are applied. These tests shall be carried out preferably from manhole to manhole. Short branch drains connected to a main drain between manholes shall be tested as one system with the main drain. In long branches, a testing junction shall be inserted next to the junction with the main drain and the branch tested separately. After the test has been passed, the testing junction shall be effectively sealed.
All openings below the top of the section to be tested shall be hermetically sealed and the pipeline shall be allowed to stand full of water for a period of fifteen (15) minutes prior to testing.
The test pressure shall be maintained for a period of one (1) hour during which time the pipe and joints shall be inspected for sweating and leakage. Any leak discovered during the tests shall be made good by the Contractor and the section re-tested to the approval of the Engineer. The time period between making good and re-testing shall be at least 24-hours.
The hydraulic test pressures shall be applied as follows.
Downstream end of test section: Not more than 3000mm head.
Upstream end of test section: Not less than 200mm head.
If the difference in level between consecutive manholes exceeds 1800mm, the maximum head on the down stream end may be increased to 4500mm.
Where the difference in level is greater than the above, the Contractor shall install approved testing equipment to carry out the test required. The test shall be carried out as long a length as possible consistent with the above.
6.3.2.5 Aboveground Drainage System
All soil, waste and ventilating pipe systems forming part of the aboveground installation shall be given a smoke test to a pressure of 38mm of water gauge.
The smoke test apparatus shall be capable of maintaining the test pressure constant for a period of fifteen (15) minutes from the time the last opening closes.
Pressure test shall be carried out before any work, which is to be concealed, is finally enclosed.
Waste and soiled water pipes shall be inspected and tested before and after installation. The complete discharge service shall be tested for soundless and performance to the satisfaction of the Engineer.
Any defects revealed by the tests shall be made good by the Contractor and the test repeated to the approval of the Engineer.
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6.3.3 Pipe Installation
6.3.3.1 Layout and Arrangements
Pre-plan and pre-arrange piping and correlate installation with work of other trades as necessary and as specified.
Incorporate minor additional changes and adjustments in layouts, routings and positions where required to avoid unnecessary interference and to provide a complete and properly operable piping system as intended under these Specifications.
Carry piping in chases or recesses in walls where provided through openings in floors and in furred ceilings. Exposed pipes shall be permitted only where shown or approved in advance.
Piping shall be free of traps or unnecessary bends.
Piping shall be arranged to conform to building requirements and to suit necessities of clearance for equipment ducts, flues, conduits or other work; including due allowance for access, maintenance and servicing.
6.3.3.2 Preparation of Pipe
Galvanized steel pipes and polyvinyl chloride pipes shall be cut using only power hacksaw, circular cutting machine with abrasive wheel, hand hacksaw, or square end sawing vice.
Black steel pipes shall be cut by oxygen-acetylene gas torch using a pipe cutting attachments.
Metallic wheel cutters shall be permitted.
Rough edges shall be removed from inside and outside surfaces of pipes.
Inside edges and burrs shall be reamed smooth and to net free bore size.
During the time work is not in progress pipe, fitting and valve ends shall be maintained closed against ingress of foreign matter.
6.3.3.3 Threaded Pipe Joint Makeup
Jointing compound or tape shall be uniformly applied only in on male threads.
Application of compound or tape into fittings shall not be permitted.
Joints shall be securely tightened free from leaks using suitable tongs or wrenches.
Leaky joints shall be disassembled, cleaned and remade using only new sealant materials.
Use of thread, cement or caulking to remake joints shall not be permitted.
6.3.3.4 Welded Pipe Joint Make-up
Welders shall be first class licensed and approved by the Engineer.
Welding shall be electric welding at the factory and/or at the job site.
Oxygen-acetylene gas shall only be permitted for pipe cutting.
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Ends of pipes shall be bevelled by suitable equipment before welding is carried out.
Joints shall be securely welded with uniform bead. Leaks of any types shall not be permitted.
Leaking joints shall be disassembled, cleaned and bevelled before being re-welded.
6.3.3.5 Flanged Pipe Joint Make-up
Gaskets shall be used between all flanges.
Bolts shall be evenly tightened around the flange to maintain an even pressure on the gasket.
Polyvinyl Chloride Pipe Solvent Weld Joint: Preparation and installation of each pipe and fitting shall conform to manufacturer’s instructions; performed only by workmen well experienced in techniques of welding plastic materials of the types required.
6.3.3.6 Reducing Fitting
Shall be required where any pipe changes.
Eccentric type reducers shall be provided where free line drainage required.
Bushing reduces shall not be permitted.
6.3.3.7 Unions and Flanges
Wherever removal for servicing or repair may be required after installation, unions or flanges shall be used as per the following schedule:
50mm or smaller pipe : Union joint
65mm or larger pipe : Flange joint
Each item shall be positioned so as to allow for easy removal of adjacent equipment, tanks, valves, etc.
Unions and flanges shall be located where shown and at the following points.
Each connection to any type of equipment and tank.
All connections to all automatic valves.
Downstream of each manually operated threaded valve.
Everywhere else necessary to facilitate assembly of piping or installation of equipment.
6.3.3.8 Installation of Water Piping
Generally the pipe work shall be levelled and free from traps or unnecessary bends or offsets.
Common Trench with Sewer Lines.
Shall be permitted only when approved by the Engineer in advance.
The bottom of the waterline shall not be less than 500mm above the top of the sewer line at any point along a common run.
The sewer and waterlines shall be separated by not less than 500mm horizontally in common trench lines.
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The bottom of the waterline shall be supported on an excavated shelf to one side of the trench; which shall not be less than the pipe size plus 200mm.
Connection to existing water distribution line shall be flanged and the location shown physically.
Flanged joints shall be made with jointing rings of best quality, hard compressed fibreboard of thickness not less than 1.5mm and such a width as to fit the inner circle of the boltholes. The rings shall be thinly smeared with graphite paint. Opposite pairs of nuts shall be carefully tightened until the joint ring is sufficiently compressed between the flanges to ensure water tightness.
Copper piping shall be jointed to steel piping by the use of copper alloy screwed unions or ferrules.
6.3.3.9 Sewer, Waste and Storm Drain
Grade shall be uniformly horizontal with sanitary or storm drain piping inside buildings graded at 10mm per 1000mm for pipe sizes 75mm and larger, unless otherwise shown.
Sewer piping shall run as straight as possible, only making changes in direction as shown on the Drawings or as required and using standard offset fittings only for the various locations required as approved.
Sewer piping shall slope uniformly between given elevations where invert elevations are shown.
6.3.3.10 Polyvinyl Chloride (PVC) Pipe
Jointing and installation shall be per manufacturer’s instructions.
Runs shall be straight and uniformly graded.
The installation shall be arranged free from unnecessary stresses on pipes or fittings.
Provisions shall be incorporated to compensate for expansion contraction as required.
Jointing for cold water supply piping shall conform to ASTM-D-2564 (Solvent for Polyvinyl Plastic Piping System).
6.3.3.11 Reinforced Concrete or Concrete Pipe Refer to Civil Works Specifications.
General
Supporting of piping or equipment by wire, plumber’s tape, rope or other means or arrangements other than as shown or specified will not be permitted.
Support component and fastenings shall be sized to adequately resist forces and stresses developed under full capacity loading, including dead loads and reactional forces under full operation and including weight of fluids conveyed and seismic forces.
The support of valves or equipment by valves or other line accessories shall not be permitted.
Lock-nuts shall be provided for each threaded connection on each hanger rod.
Vertical Piping through Floors
Riser shall be clamped with extended arms resting on at least each floor.
The support spacing shown or specified are the maximum permitted.
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In addition at changes in direction in either the vertical or horizontal plane, a support device shall be provided near the point of change of direction except this may be omitted when in coincides with the required typical spacing location.
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7 INTERNAL HEATING INSTALLATIONS
7.1 PRE INSTALLATION
Before cutting, cementing, welding, soldering, screwing pipework prior to installation the Contractor shall establish the length of the columns and of the connections of the heating bodies, of the distribution pipes.
In order to correctly establish the length account shall be made of:
the position of the pipes from the walls and boards;
the position of the heating bodies;
the slopes stipulated by the project, for providing a correct circulation of the heat carrier;
the distances between the axes of the fittings and the plates mounted on the pipe;
the length of the ramifications and of the ramification angles;
the length and the height of the rooms the pipes are going through;
the position of different aggregates and the connection place of the pipes;
the routes of the other neighbouring installations.
7.2 PIPE INSTALLATION
Pipework shall be protected where it passes through the walls/floors.
Pipes shall be installed on the shortest route between the distributor-collectors and the radiators.
The pipework shall be suitable for temperatures from –400 C to 900 C (accidentally 1100 C) and up to 10 bar.
Connection fittings shall be suitable for the pipe material and for use in heating installations.
Elbows and bends shall be used where required to maintain the diameter of the pipes. Pipe bends shall have a radius of curvature maximum 5D.
Only special tools designed for installation of pipework shall be used.
Pipes shall be fixed with mounting plates, fixing screws, clamps, clips.
At their delivery, the pipes must be accompanied by the Certificate of quality and by the ISCIR approval for import where appropriate.
7.3 MOUNTING THE PLANT ANCILLARIES
All the fittings shall be mounted in the “closed” position. Depending on the mounting place, the valves may be mounted with the hand wheel up or down. After mounting the valves shall be closed and opened to test their action.
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7.4 MOUNTING THE HEATING PLANT
Mounting of the radiators shall be done in the following order:
marking the position of the radiator;
marking position of supports;
fixing the radiator.
The following mounting distances will be taken into account when tracing the position of the radiator:
the minimum distance between the heating body and the wall shall be 5 cm;
the distance between the heating bodies and the floor shall be 12 cm.
The support brackets shall be embedded into the wall with cement mortar on a depth of 5 cm or fixed through screw shooting (excepting the BCA walls).
When using floor mounted supports their position shall be marked by observing the same rules as for wall brackets. These supports shall be marked and fixed only after finishing the floor.
7.5 HEATING PLANT
The heating plant shall be installed according to the technical regulations ISCIR C31-84 and to its technical manual. The equipment shall be mounted and connected to the installations in strict accordance with the stipulations of the technical documentation presented by the supplier. They shall be put into service only after the approval of the Engineer.
7.6 ACCEPTING THE WORKS
The following normative acts shall be taken into consideration when accepting the works:
C 56- norm for checking the quality of the construction works and afferent installations
I 25- technical instructions for hydraulic and pneumatic tests in tanks.
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8 CONSTRUCTION OF PIPELINES AND ANCILLARY WORKS
8.1 PIPELAYING GENERALLY
Where socketed pipes are required to be laid on a granular or sand bed, or directly on a trench bottom, joint holes shall be formed as described in this specification.
Pipes shall be laid on setting blocks only where a concrete bed or cradle is used.
No protective cap, disc or other appliance on the end of a pipe or fitting shall be removed permanently until the pipe or fitting which it protects is about to be jointed. Pipes and fittings, including any lining or sheathing, shall be examined for damage and the joint surfaces and components shall be cleaned immediately before laying.
Suitable measures shall be taken to prevent extraneous material from entering pipes, and to anchor each pipe to prevent flotation or other movement before the Works are complete.
Where pipeline marker tape is specified, it shall be laid between 100 mm and 300 mm above the pipe. Where a tracer system is specified it shall be continuous and adequately secured to valves and fittings.
A detectable marker tape, in accordance shall be laid above all polyethylene or non metallic pipes.
The minimum depth of cover to the crown of the pipe shall be 900 mm or below frost depth unless otherwise specified in the Contract.
The minimum depth of cover to sewers under tracks and roads shall be 1200 mm unless otherwise approved by the Engineer.
Where it is necessary to lay with a cover of less than 900 mm, the pipeline shall be adequately protected as approved or directed by the Engineer.
At every point of loading or unloading, pipes or castings must be handled by approved lifting tackle. Unloading by rolling down planks or any other form of inclined ramp will not be allowed unless the written consent of the Engineer to the method proposed has been obtained.
Pipes shall only be lifted using approved slings in accordance with the manufacturer’s instructions.
8.2 PIPE BEDDING
Bedding for pipes shall be constructed by spreading and compacting granular bedding material over the full width of the pipe trench. After the pipes have been laid, additional material shall, if required, be placed and compacted equally on each side of the pipes, and where practicable, this shall be done in sequence with the removal of the trench supports.
Where trenches have been excavated and groundwater is likely to flow in any granular bed and surround to the pipe, and if feasible in the prevailing ground conditions, the Contractor shall provide suitable impermeable clay stanks at a maximum spacing of 50 m along the length of the trench.
8.3 CONCRETE PROTECTION TO PIPES
Pipes to be bedded on or cradled with concrete shall be supported on precast concrete setting blocks, the top face of each block being covered with two layers of compressible packing.
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Concrete provided as a protection to pipes shall be Grade C20, placed to the required depth in one operation.
Where pipes with flexible joints are used, concrete protection shall be interrupted over its full cross-section at each pipe joint by a shaped compressible filler.
Rapid hardening cement shall not be used in concrete for the protection of plastics pipe.
Where plastic pipes are partially or completely surrounded in concrete, the pipe or fittings shall be wrapped in heavy gauge polyethylene sheet or tube to allow the pipe to move slightly under the action of internal pressure and avoid stress concentration on the rigid/flexible interface.
At detachable flexible couplings a clearance of 50 mm shall be left at each side of the coupling.
8.4 COMPLETION OF PIPE SURROUND
After completion of the relevant operations fill material shall, where required, be placed and compacted over the full width of the trench in 2 equal layers to a finished thickness of 250 mm above the crown of the pipes.
Subsequent filling shall then be carried out.
8.5 THRUST BLOCKS
Except where welded steel pipelines or self anchoring joints are used, thrusts from bends and branches in pressure pipelines shall be resisted by concrete thrust blocks cast in contact with undisturbed ground.
Any additional excavation required to accommodate thrust blocks shall be carried out after the bend or branch is in position and the thrust face shall be trimmed back to remove any loose or weathered material immediately prior to concreting.
Thrust blocks shall be allowed to develop adequate strength before any internal pressure is applied to the pipeline.
Rapid hardening cement shall not be used in concrete for thrust blocks to plastic pipes.
8.6 PIPE JOINTING GENERALLY
Pipe jointing surfaces and components shall be kept clean and free from extraneous matter until the joints have been made or assembled. Care shall be taken to ensure that there is no ingress of grout or other extraneous material into the joint annulus after the joint has been made.
Where pipes with flexible joints are required to be laid to curves, the deflection at any joint as laid shall not exceed three quarters of the maximum deflection recommended by the manufacturer.
The Engineer may direct that laying and backfilling may proceed without the need for joints to be inspected, but this will not relieve the Contractor of his responsibility to excavate and permit the inspection of the joints during the testing of the pipeline, if necessary.
8.7 WELDED JOINTS IN PLASTIC PIPES
Fusion welded joints in high density and medium density polyethylene pipes shall be made only between pipes having the same physical characteristics. Joints between pipes from different manufacturers shall only be made with the specific approval of the Engineer.
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Site fusion jointing shall be made in accordance with manufacturer's instructions.
When solvent welded PVC-U pipes are jointed outside the trench, they shall not be lowered into place until the period recommended by the manufacturer for complete setting of the joints has elapsed.
A pipe section containing a completed weld shall achieve the same strength characteristics as the parent pipe.
Heat fusion jointing of polyethylene pipes shall only be carried out by operatives who have undertaken training in accordance with National requirements. Documentary evidence of successful completion of the training course shall be submitted to the Engineer for approval prior to the operative commencing work on heat fusion jointing.
The ovality of straight polyethylene pipes shall not exceed 2% in diameters up to and including 250 mm, and 3.5% in diameters over 250 mm. The ovality at any section in a coiled pipe after uncoiling shall not exceed 12%. Coiled pipe shall be re-rounded for electrofusion jointing by use of suitable clamps and/or approved inserts.
8.8 FLANGED JOINTS
Flanges shall be properly aligned before any bolts are tightened.
Jointing compounds shall not be used when making flanged joints, except that, to facilitate the making of vertical joints, gaskets may be secured temporarily to one flange face by a minimum quantity of clear rubber solution. Both threads shall be treated with graphite paste and the nuts tightened evenly in diametrically opposite pairs.
The sequence and torques applied in tightening bolts shall conform with the manufacturer's instructions. Torque wrenches shall be used.
8.9 WELDED JOINTS IN STEEL PIPES
The process of welding steel pipelines and type of joint shall be in accordance with the Contract.
The ends of pipes shall be cut or prepared as appropriate, and be free from fins, planar defects, tears and other surface defects, prior to welding. Cleaning to base metal shall extend for at least 25 mm from the end of pipe on both internal and external faces.
The alignment of abutting pipe ends shall be such as to minimise the internal offset between surfaces.
The Contractor shall submit details of the proposed welding and welding repair procedures, before production welding begins, and test welds using these procedures shall be made by the Contractor under simulated site conditions.
Welders shall only make welds for which they are qualified and approved.
Joints shall be tested using non-destructive techniques, unless it is necessary to use destructive testing to achieve adequate interpretation.
All joints on welded steel pipes shall have protection after any requirements for electrical continuity bonding have been met.
Elastomerically sealed joints will not be permitted unless specified elsewhere in the Contract.
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8.10 PROTECTION OF FERROUS PIPES, JOINTS AND FITTINGS
Ferrous pipes, joints and fittings shall be cleaned and all loose rust removed before protection is applied.
External protection for joints and fittings shall comprise:
P1 – the application of a thin continuous coating of petroleum paste over the whole area to be protected as a primer. Where bolt heads, nuts, flanges and other projections arise, a profiling mastic shall be used to give a smooth external profile. The joint or fitting shall be wrapped with a protective tape. The minimum application shall be a spiral wrap using 55% overlap. The tape shall extend along 150 mm of the barrel of the pipe on each side of the joint or fitting.
or
P2 - The application of a continuous coating of bitumen primer over the whole area to be protected. Where bolt heads, nuts, flanges and other projections arise, a profiling mastic shall be used to give a smooth external profile. The joint or fitting shall be wrapped with a self adhesive, cold applied rubber bitumen tape with a PVC backing. The minimum application shall be a spiral wrap using 55% overlap. The tape shall extend along 150 mm of the barrel of the pipe on each side of the joint or fitting.
or
P3 – The application of heat shrink sleeves.
External protection for ductile iron pipes shall comprise:
P4 – The covering of the pipes with lay flat polythene sleeving securely held in place with adhesive tape at pipe joints and intermediate positions.
or
P5 – The factory application of plastic sleeving.
or
P6 - The factory application of plastic tape.
or
P7 – Painting the external surface as described in the Contract.
Completion of internal and external protection of steel pipes shall be provided where pipes have a bituminous, epoxy or any other type of proprietary protective coating in which a gap has been left for the joint to be made. The joint and any damage to the protective coating shall be made good.
After installation, all unburied ferrous pipework, including that in chambers, shall be prepared and painted with 2 coats of protective paint to a minimum dry film thickness of 80 microns.
Cathodic protection of pipes, joints and fittings shall comprise either impressed current or sacrificial anode.
The Contractor will be responsible for obtaining all necessary permits and authorisation for use of cathodic protection of pipes.
8.11 CUTTING PIPES
Pipes shall be cut by a method which provides a clean square profile, without splitting or fracturing the pipe wall, and which causes minimal damage to any protective coating. Where necessary, the cut ends of
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pipes shall be formed to the tapers and chamfers suitable for the type of joint to be used, and any protective coatings shall be made good, and the ends sealed.
Where ductile iron pipes are to be cut to form non-standard lengths, the Contractor shall comply with the manufacturer’s recommendations in respect of ovality correction and tolerances to the cut spigot end.
Where concrete pipes are cut any exposed reinforcement shall be sealed with an epoxy resin mortar.
Full surround clamps shall be used when cutting PVC-U pipes.
All personnel involved in cutting asbestos products must wear adequate respirators and comply with acceptable health and safety procedures.
8.12 PRECAST CONCRETE MANHOLES
Precast concrete chamber and shaft sections shall be constructed with steps and step rungs, irons, ladders or slabs aligned correctly.
Joints shall be made so that the required jointing material fills the joint cavity. Any surplus jointing material extruded inside the chamber or shaft shall be trimmed off and joints shall be pointed on completion.
Each construction joint shall break joint with that of the chamber or shaft sections by at least 150 mm.
8.13 INVERTS AND BENCHING
Manhole inverts and benchings shall be formed of the materials described in the Contract and where there is no change of diameter, the invert shall follow the same gradient as the outgoing sewer.
Where inverts and benchings are to be formed of in-situ concrete or high strength concrete topping (granolithic finish), the relevant provisions of this specification shall apply.
Where a high strength concrete topping (granolithic finish) is required, the invert and benching shall be formed in concrete with a Screeded Finish or Rough Finish as required, and the concrete topping shall be applied as soon as practicable thereafter.
Where the inverts of both manhole and sewer are constructed of brickwork, there shall be no break in bond between the two.
8.14 PIPES AND JOINTS ADJACENT TO STRUCTURES
A flexible joint shall be provided as close as is feasible to the outside face of any structure into which the pipe is built, compatible with the subsequent movement of the joint.
The length of the next pipe (rocker pipe) away from the structure shall be as set out below:
Nominal Diameter (mm) Effective Length (m)150 to 600 0.6600 to 750 1.0over 750 1.25
A pipeline may, where practicable, be laid through a manhole and the crown cut out to the half diameter, providing flexible joints are situated on each side, no further than 600 mm from the inner face of the manhole wall, and that adjacent pipes comply with this Clause.
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8.15 WATERTIGHTNESS OF MANHOLES AND CHAMBERS
Manholes and chambers shall be substantially watertight, with no identifiable flow of water penetrating the permanent Works.
8.16 SETTING MANHOLE COVERS AND CHAMBERS
Manhole frames shall be set to the required level on brickwork, or on precast concrete cover frame seating rings, as described in the Contract. The frames shall be set to level, bedded and haunched over the base and sides of the frames in mortar.
8.17 CONNECTIONS TO EXISTING SEWERS
Pipe saddles for PVC-U pipes shall be purpose made from PVC-U and shall either be of a mechanical clip-on type or shall be fixed with an appropriate solvent cement.
Purpose made junctions may be used by cutting out sections of pipe, fitting a junction and securing with repair couplings. Alternatively, where an appropriate saddle or junction unit is not obtainable, a connection to an existing sewer may be made with a pipe cut to give an oblique junction, so that the discharge is in the direction of flow in the main sewer. The connecting pipes shall be of such a length that the socket of the cut pipe rests on the outside barrel of the sewer with no projection inside the main sewer. The pipe joint shall then be pointed in mortar (over the whole pipe circumference) externally, and internally where practicable.
The ends of connections and pipes not required for immediate use shall be closed with purpose made stoppers, discs or joinders. The position of all junctions shall be recorded by the Contractor by measurement from the manhole immediately downstream and notified to the Engineer before backfilling is commenced.
8.18 MARKERS AND INDICATOR POSTS
Marker and indicator posts shall be erected to show the location of the following:
Valves
Fence or boundary crossings
Hydrants
Air Valves
Washouts
The Contractor shall present a schedule clearly identifying the marker posts to the Engineer on completion of the Contract.
Bases shall be set 400 mm below ground level in a 400 mm diameter footing of concrete Grade ST1 completely filling the post holes up to ground level.
8.19 TOLERANCES FOR PIPELINES
The line and level of any pipeline shall not deviate from that described in the Contract by more than 20 mm.
Notwithstanding the tolerances specified the deviation from the specified levels shall not cause a backfall in any gravity pipeline.
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8.20 INSTALLATION OF VALVES AND PENSTOCKS
The Contractor shall store valves and ancillary apparatus in clean dry conditions. Headstock, motors, gearing and indicators shall be removed, adequately labelled for identification, stored in weatherproof premises and shall be refitted after the installation of the valves. Electrical equipment shall be protected from damp and the damp proofing seals shall remain intact until ready for installation.
All valves shall be installed within valve chambers unless otherwise described in the Contract.
Gunmetal faces and seats of valves shall be kept clean. No valve shall be closed without first wiping the faces with a clean cloth and thoroughly cleaning the cavity beneath the valve gate by hand.
All valves shall be set so that operating spindles are truly vertical unless otherwise specified.
Before a valve is put into service, gears, bearings and spindles shall be greased or oiled with an approved lubricant. Oil baths shall be cleaned and topped up to the appropriate levels and all grease nipples charged with grease. No deleterious matter shall be allowed to come into contact with the working faces and oil sumps shall be maintained in a clean condition.
Stuffing boxes shall be examined when the pipeline is charged and leaking boxes adjusted or repacked with square plaited lubricated hemp packing where appropriate. Stuffing boxes shall not be so tightly packed as to impede the rotation of the spindle.
The installation of special types of valve and metering equipment shall be strictly in accordance with the manufacturer’s instructions.
8.21 LAYING CABLE DUCTS
For the purposes of the Specification a cable duct shall be regarded as a pipeline.
Cable ducts shall be laid with a 75 mm bed and surround of sand.
Draw cords shall be inserted and left in the cable ducts. After installation of drawcords, ducts shall be plugged and the cord fastened at each end of the duct.
Within all duct draw pits a bellmouth shall be formed at the ends of all ducts to prevent cables becoming snagged during the installation.
Cable ducts shall be installed to comply with the minimum depth and separation requirements stated in the electrical specification.
Where ducts are laid beneath roads, the ducts shall be surrounded in 150 mm minimum concrete surround for the full width of the road and extending each side by at least 500 mm beyond the back of the kerb.
Draw pits shall be provided to changes of direction and at a spacing of not less than 50m.
All ducts terminating in buildings shall extend 150 mm above final floor level.
8.22 CONNECTIONS TO EXISTING PIPELINES
Connections to existing pipelines shall be made by the Contractor only at times which are agreed in advance with the Engineer. The Contractor shall give the Engineer written notice at least 7 days before the date on which he wishes to make the connection and shall not proceed with it until he has received the Engineer's approval in writing.
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The Contractor shall plan his construction work to minimise interference with the existing operations. This may involve the Contractor working outside normal working hours.
The Contractor shall not remove any cap, thrust block or fitting from any existing pipeline or interfere with it in any way whatsoever, or break into any existing structure without a written authorisation from the Engineer.
When the Contractor is required to make a connection to an existing pipeline, the Contractor shall verify before starting work on the connection, if necessary by excavating trial pits, that the material to be furnished under the Contract will be suitable for making the connection.
In planning connections to existing pipework, the Contractor shall assume that isolating valves and washout facilities are generally not available and plan his work accordingly.
8.23 MAINTAINING WATER SUPPLIES TO CUSTOMERS
In cases where the Contractor causes a prolonged interruption in the operation of live water pipes during installation of new pipelines, he shall provide replacement temporary pipework to ensure continuity of water supply. This shall include, where necessary and approved, laying temporary pipework on the surface.
Prior to being brought into service, any temporary pipework shall be disinfected.
8.24 LAGGING TO EXTERNAL PIPEWORK
Pipe lagging shall be provided as required by the Contract to eliminate the risk of pipework freezing under normal operating conditions when the ambient temperature is below -10oC.
If trace heating is to be provided then this shall be completed before lagging is undertaken.
At pipe joints and at fittings and valves the thickness of lagging shall be maintained to all parts of the item being lagged.
Lagging and cladding shall not prevent the proper operation of any components. All valves shall have removable covers to allow access for maintenance.
Removable flange boxes shall be provided at all flanges to permit future dismantling of the pipework without damage to the insulation.
8.25 MAINLAYING AND SERVICE RECORDS
The Contractor shall keep a daily record of all pipes, services and fittings laid in their order of laying, together with their length, depth to invert of pipe at the end of each pipe, description of surface and location.
The Contractor shall keep a record of all the services encountered in the pipe trench. This record shall contain a description of the type of service, its size, depth and location along the pipeline. The angle at which the service crossed the trench is also to be recorded.
Records shall be submitted to the Engineer by the Contractor on a weekly basis.
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8.26 PROGRESS OF PIPELINE CONSTRUCTION
Every trench shall be backfilled around the body of each pipe within 8 hours of jointing, except by permission of the Engineer. The trench shall be completely backfilled and cleaned up after each section of pipe has been inspected, tested and approved.
All construction debris, excess excavation, and other materials are to be cleaned up and restoration completed of all fences, ditches, culverts, signposts, and similar items immediately following the final backfilling of the pipeline.
8.27 WORK IN HIGHWAYS
The centreline of road shall be avoided where pipelaying cannot be undertaken without disrupting traffic in both directions, or even closing the road.
Any proposed pipeline alignment shall be agreed with the Engineer.
Pipelines shall be constructed to alignments that cause minimum inconvenience to other parties during laying and subsequent operation or repair.
The Contractor shall not make use of the public streets, roads, verges, thoroughfares or footpaths for disposing or storing equipment or materials other than such equipment, plant, materials, tools and implements as shall from time to time be required for immediate use on the section of the highway in question.
In carrying out the Works, the Contractor shall deposit excavated materials, pipes, construction materials and site equipment, offices, etc., in such a way as to cause minimum interference with the use of highways by the public, and shall maintain those parts of the highways not temporarily occupied by the Works in a clean, passable and safe state at all times.
8.28 HYGIENE AND CLEANLINESS
It is imperative that pipes, specials and fittings for use in potable water supply shall be kept scrupulously clean internally from the time of delivery or collection until the pipeline is commissioned. The Contractor shall take every precaution to prevent contamination of the pipes from any source, and immediately before any potable water pipe or special is laid it will be pulled through with a suitable swab soaked in chlorine solution. All fittings will be washed off with chlorine solution immediately before being installed. The chlorine solution shall be applied by spray which shall be standard equipment for any gang employed in the Employer's area. No laying of potable pipework shall be permitted without this compliance.
During the laying and jointing operation, any deleterious matter or liquid that may enter a pipe shall immediately be washed out and the pipe lining swabbed.
After each successive pipe is laid, its open end shall be closed with a watertight stopper which shall not be removed until the next pipe is laid and ready for jointing. The open end of the first pipe in each length of pipeline shall be similarly plugged and shall remain so until it is closed with the adjacent length.
No protective cap, disc or other appliance on the end of a pipe or fitting shall be removed permanently until the pipe or fitting which it protects is about to be jointed. Pipes and fittings, including any lining or sheathing, shall be examined for damage and the joint surfaces and components shall be cleaned immediately before laying.
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9 TESTING AND DISINFECTION
9.1 CLEANSING OF PIPES
On completion of construction, and before any disinfection, internal surfaces of all pipelines shall be cleaned thoroughly.
9.2 PRECAUTIONS PRIOR TO TESTING PIPELINES
Before testing any pipeline, the Contractor shall ensure that it is anchored adequately and that thrusts from bends, branch outlets or from the pipeline ends are transmitted to solid ground or to a suitable temporary anchorage.
Open ends shall be stopped with plugs, caps or blank flanges properly jointed.
It will not be permissible to transmit the thrust on to a completed length of piping or on to existing pipelines from which the pipeline is being filled.
Before the pressure testing of the pipeline is carried out, the trench shall be sufficiently refilled to ensure that the requisite anchorage is provided for each pipe as will prevent movement during the testing period.
Adequate provision for the release of air from the pipeline must be made at any high points and blank flanges.
Potable water shall be used for the cleansing, testing and swabbing of water pipelines unless otherwise directed by the Engineer.
9.3 TESTING METHOD PROGRAMME AND NOTIFICATION
Before any testing of a pipeline, the Contractor shall submit a programme of testing and swabbing to the Engineer.
The Contractor shall notify the Engineer at least 2 working days beforehand of his intention to test a section of pipeline.
On completion of mainlaying and sectional testing and before leaving the site, the whole pipeline shall be subjected to an overall comprehensive pressure test. The approval of the Engineer is to be sought for the testing arrangement before the tests commence.
The Contractor shall be solely responsible for deployment of his labour, equipment and materials during the period of notice and test, and no claims for extra payment for unproductive time in this period shall be made.
Tests shall be against blank flanges or end caps. Tests against closed valves shall not be permitted unless specified elsewhere in the Contract.
The Contractor shall take all reasonable precautions to prevent any undue wastage of water, and shall provide, fix, maintain and work all necessary storage tanks, pumps, pipes, cocks, fittings, hoses and other appliances as necessary.
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9.4 TESTING NON-PRESSURE PIPELINES
Non-pressure pipelines laid in open cut shall be tested after they are jointed and before any concreting or backfilling is commenced, other than such as may be necessary for structural stability whilst under test.
The pipelines shall be tested by means of an air or water test or by a visual or close circuit television (CCTV) inspection (as agreed with the Engineer), in lengths determined by the course of construction, in accordance with a programme approved by the Engineer.
A further test shall be carried out after the backfilling is complete.
9.5 WATER TEST FOR NON-PRESSURE PIPELINES
The test pressure for non-pressure pipelines up to and including 750mm nominal bore shall be not less than 1.2m head of water above the pipe soffit or ground water level, whichever is the higher at the highest point, and not greater than 6m head at the lowest point of the section. Steeply graded pipelines shall be tested in stages in cases where the maximum head, as stated above, would be exceeded if the whole section were tested in one length.
The pipeline shall be filled with water and a minimum period of 2 hours shall be allowed for absorption, after which water shall be added from a measuring vessel at intervals of 5 minutes and the quality required to maintain the original water level noted. Unless otherwise specified, the length of pipeline shall be accepted if the quantity of water added over a 30 minute period is less than 0.5 litre per linear metre per metre of nominal bore.
9.6 AIR TEST FOR NON-PRESSURE PIPELINES
Non-pressure pipelines to be air tested shall have air pumped in by suitable means until a pressure of 100 mm head of water is indicated in a U-tube connected to the system. The pipeline shall be accepted if the air pressure remains above 75 mm head of water after a period of 5 minutes without further pumping, following a period for stabilisation. Failure to pass the test shall not preclude acceptance of the pipeline if a successful water test, ordered by the Engineer, can subsequently be carried out.
9.7 CCTV INSPECTION OF PIPELINES
CCTV inspections shall comply with recognised current European Model Contract forms.
For all gravity sewer pipelines the Contractor shall undertake a CCTV survey using a rotating head/lens, colour, high resolution camera and provide the Engineer with a copy of the video recording and report.
9.8 INFILTRATION
Non-pressure pipelines (including tunnels) and manholes shall be tested for infiltration after backfilling. All inlets to the system shall be effectively closed, and any residual flow shall be deemed to be infiltration.
The pipeline including manholes shall be accepted as satisfactory if the infiltration, including infiltration into manholes, in 30 minutes does not exceed 0.2 litre per linear metre per metre of nominal bore.
Notwithstanding the satisfactory completion of the above test, if there is any discernible flow of water entering the pipeline at a point which can be located either by visual or CCTV inspection, the Contractor shall take such measures as are necessary to stop such infiltration.
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9.9 TESTING OF PRESSURE PIPELINES (EXCLUDING PVC AND POLYETHYLENE PRESSURE PIPES)
The entire pipeline shall be pressure tested.
Gauges used for testing pressure pipelines shall either be of the conventional circular type, not less than 200mm diameter, calibrated in metres head water, or shall have a digital indicator capable of reading increments of 0.1m head. Before any gauge is used, the Contractor shall arrange for it to be checked independently and a dated certificate of its accuracy shall be provided.
Before testing, valves shall be checked and sealed, the sections of pipeline filled with water and the air released. After having been filled, pipelines shall be left under operating pressure for 24 hours, so as to achieve conditions as stable as possible before commencing testing.
The pressure in the pipeline shall then be raised steadily until the specified test pressure is reached in the lowest part of the section, and the pressure shall be maintained at this level by pumping if necessary, for a period of one hour. The pump shall then be disconnected, and no further water shall be permitted to enter the pipeline for a further period of one hour. At the end of this period the original pipeline until the pressure as at the end of the test is again reached.
The permissible loss shall not exceed 2 litres per metre nominal bore per kilometer length per metre head (calculated as the average head applied to the section) per 24 hours.
Test pressures shall be 1.5 x working pressure, with a minimum of 6 bars, except where instructed by the Engineer.
All testing apparatus and materials including cap-ends, blank flanges, etc shall be provided by the Contractor. The Contractor shall provide all labour, plant and materials to carry out the pressure testing.
The Contractor shall be responsible for the supply of water for pressure testing. Water for disposal must be channelled to the nearest available watercourse/stormwater drainage system as approved by the Engineer.
For the duration of the test air valves shall be isolated, valve gland packings shall be tightened down where applicable, and re-adjusted on completion of the successful test.
Air tests shall not be permitted.
Hydrostatic testing of steel pressure pipelines shall be carried out as specified in the relevant National guidelines. The test pressure for steel pipelines shall be a minimum of 1.5 times the working pressure.
For all other pressure pipelines the test pressure shall not be less than the maximum pressure under surge conditions or the maximum pressure caused by pumping against a closed valve.
The test pressure at the lowest point in the pipeline shall not exceed the maximum pressure recommended for the pipe being tested.
Where a new pipeline is to connect to an existing pipeline, the new pipeline shall be tested up to the point of connection. After testing the connection shall be made up and left exposed for visual inspection by the Engineer. The pipeline shall be accepted if no leakage can be detected under normal operating pressure after a period of 24 hours.
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Prior to testing any pressure pipeline the Contractor shall submit for the Engineer’s approval details of all temporary thrust blocks. These details shall be submitted with sufficient calculations to demonstrate that the thrust blocks will resist the specified test pressure. The Contractor shall submit these details at least 10 working days before the commencement of the particular test.
9.10 TESTING OF PVC AND POLYETHYLENE PRESSURE PIPES
Testing is to be done in accordance with the manufacturer's recommendations.
The hydrostatic test pressure for polyethylene pipes shall be 1.5 times the rated pressure for systems rated up to 10 bar and 1.5 times the working pressure for 12 or 16 bar systems.
Hydrostatic testing of PVC-U pipelines shall be carried out as specified in the relevant National guidelines or in accordance with manufacturer's instructions. The test pressure for PVC-U pipes shall be the greater of the rated pressure and 1.5 times the working pressure.
9.11 SWABBING OF WATER PIPELINES
On completion of the hydraulic test on water pipelines, foam swabs shall be passed through the pipeline for final cleansing sufficient times to achieve clear wash water.
Recovery of swabs shall be witnessed by the Engineer.
The Contractor shall provide all swabs and temporary pipework.
Swabbing shall be undertaken using a hard scour swab followed by a soft foam swab. Both swabs shall be passed through the pipeline during the same swabbing operation.
Swabbing operations shall be repeated until the flushing water runs clear.
The swabs shall be checked visually for cleanliness and shall have been soaked, immediately prior to use, overnight in 5 mg/l of chlorine solution. The space between the swabs shall also be filled with this solution.
Only the Employer’s staff shall operate their own valves where necessary, and the Contractor shall provide the Engineer with a minimum of 2 days notice so that the appropriate attendance can be arranged.
9.12 DISINFECTION, SAMPLING AND OPERATION OF WATER PIPELINES
After disinfection, bacteriological and chemical sampling of completed sections of water pipelines and communication pipes, the Contractor shall not turn any valves or take any other action which might interfere with the use of the pipeline.
Bacteriological sampling of completed sections of potable water pipelines shall be carried out by the Employer unless otherwise stated in the Contract.
The Contractor shall comply with the following procedure when carrying out chlorination.
a) The Contractor shall provide points on the pipelines at which samples are to be taken to check on chlorine levels of the water in the pipeline or to obtain bacteriological samples. Where possible use shall be made of hydrant/washout and air valve locations.
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b) Prior to the commencement of chlorination, the potable water pipeline shall be swabbed and pressure tested as specified elsewhere, and left fully charged with water.
c) During the chlorination procedure, precautions shall be taken to ensure that highly chlorinated water cannot enter the existing distribution system. The only link between the existing system and the new pipeline shall be through a temporary connection, e.g. a fire hose between two hydrants including double non-return and check valves which shall be disconnected when not in use.
d) Chlorination using chlorine gas or sodium hypochlorite solution approved by the Engineer shall be carried out by causing water to flow at a constant rate into the pipeline from the existing distribution system, whilst the chlorinating agent is injected continuously at a sufficient rate to maintain a free chlorine residual of not less than 25 milligrams per litre (mg/l). This minimum chlorine residual shall be present throughout the whole length of the pipeline. The passage of a slug of highly chlorinated water through the pipeline shall not be acceptable.
e) The pipeline shall be left to stand with this concentration for a minimum of 24 hours.
f) On all pipelines, all valves and hydrants shall be operated several times to ensure that the chlorinating solution comes into contact with all parts.
g) After 24 hours' contact, the chlorinating solution shall be flushed out with mains water, including flushing out each fitting and the ends of every branch off the pipeline. The chlorine residual shall be frequently checked. Flushing can cease when the chlorine residual found is no greater than that of the incoming water.
h) After flushing out the highly chlorinated water the new pipeline shall be left filled with mains water and left for a further 24 hours before sampling is carried out.
i) Samples shall be taken by the Employer of the incoming mains water and from the end of the pipeline and all its branches. In the case of long pipelines, sufficient samples will be taken to represent overall quality. Chlorine residuals shall be measured at the time of sampling. The pipeline shall not be accepted as satisfactorily disinfected until all samples obtained from it comply with the Employer's potable water quality standards.
j) The Contractor shall allow at least 3 working days for results to become available after sampling and will they will only be satisfactory if no coliform or E.coli organisms per 100 ml are found.
k) In the event of unsatisfactory samples, all or part of the swabbing and disinfection procedure shall be repeated at the discretion of the Engineer.
l) Once a successful bacteriological test has been completed the final connections shall be made and the pipeline brought into service within 72 hours.
The Contractor shall provide all labour, all necessary fittings, pumps (dewatering, filling and driving), temporary pipework, tappings and connections for transferring water from the nearest adequate water supply, chlorinating and de-chlorinating equipment and materials, and all other apparatus required to comply with this Clause.
9.13 CLEANSING OF STRUCTURES
On completion of construction, and before any disinfection, internal surfaces of structures designed to retain an aqueous liquid shall be cleaned thoroughly in such a way as to remove all oil, grit and other deleterious matter.
Unless otherwise directed by the Engineer, only potable water is to be used for the cleansing, testing and sterilisation of structures.
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9.14 TESTING OF CONCRETE ROOFS
Concrete roofs of structures which are to contain water shall be watertight and shall, where practicable, be tested prior to the installation of any waterproof membrane by ponding with water to a minimum depth of 25 mm for a period of 24 hours.
Where this is impracticable, the roof shall be thoroughly wetted by continuous hosing of not less than 6 hours.
In either case, the roof shall be regarded as satisfactory if no leaks or damp patches show in the soffit.
The roof covering shall be completed as soon as possible after satisfactory testing.
9.15 TESTING OF WATER RETAINING CONCRETE STRUCTURES
After cleaning and as far as practicable before any filling is placed against the outside wall faces, water retaining structures shall be filled at a uniform rate of not greater than 2 m in 24 hours. A period of 3 days shall be allowed by the Contractor for stabilisation, after which the water level shall be recorded by approved means at daily intervals for a 7 day test period. During the test period the total allowable drop, after allowing for evaporation and rainfall, shall not exceed 1/500 of the average water depth of the full structure or 10 mm, whichever is the less.
Notwithstanding the satisfactory completion of the above test, any leakage visible on the outside faces of the structure shall be stopped. Any caulking or making good of cracks in the walls shall, where practicable, be carried out from the inside face.
The hydraulic test shall only be carried out after successful completion of a roof test.
Adjacent internal chambers within a structure shall be tested sequentially with the adjacent chambers empty.
On satisfactory completion of the test, the structure shall be emptied as far as practicable, unless the water can be used for subsequent activities.
For open topped structures the Contractor shall supply and locate, adjacent to the structure to be subjected to the test, an open plastic tank of minimum plan area of 1m 2. This tank shall be filled to 50 mm below the top and a level gauge used to assess allowance for rainfall and evaporation during the test on the structure.
Where there are internal compartments these shall be tested separately.
9.16 DISINFECTION OF STRUCTURES FOR POTABLE WATER
Immediately before acceptance of any structure for potable water, the interior shall be disinfected using water chlorinated to give a residual of not less than 50mg/l of free chlorine. The structure shall be emptied, flushed with mains water and then filled with water having a chlorine residual of not more than 0.5mg/l free chloride to normal top water level.
After 24 hours the Engineer shall arrange for a sample to be taken for bacteriological analysis.
The structure shall be deemed to be disinfected if there are no coliforms in the sample. If there are coliforms in the sample the Engineer shall arrange for one further sample to be taken and the structure shall be deemed to be disinfected if there are no coliforms in that sample.
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Once a successful bacteriological test has been completed the structure shall be brought into service within 24 hours otherwise re-sterilisation shall be required and the procedure repeated.
9.17 WATER FOR TESTING, SWABBING AND DISINFECTION
Water for testing, swabbing and disinfection of pipes and structures may be taken from existing supply if the Contract so provides. The Contractor shall make arrangements with the water supply authority for these supply facilities or make alternative arrangements if necessary.
Stand pipes used for obtaining water from the public supply system shall be to the approval of the water supply authority and shall be submitted to them for inspection and approval if required.
A check valve system shall be incorporated in the system between the public supply pipeline and the pipeline or structure being filled to prevent back-siphonage.
Water for cleansing, testing and sterilisation shall only be taken at times and in a manner approved by the Engineer and the water supply authority.
9.18 DISPOSAL OF WATER FROM CLEANSING, TESTING OR DISINFECTION
Facilities shall be provided for the removal and disposal of water used for disinfection, swabbing or testing.
Discharges to sewers shall not take place without the consent of the Sewerage Authority.
Water used in the cleansing, testing or disinfection of structures or pipelines shall be rendered safe prior to discharge to the environment.
Following a water test, pipelines and structures shall be emptied as far as practicable.
Discharge of chlorinated water to a water course, road gullies or surface water drains shall be done with due care to the environment.
Where suitable facilities for disposal of chlorinated water are not available, de-chlorination must be carried out prior to disposal.
9.19 TESTING OF NON-CONCRETE WATER RETAINING STRUCTURES
After cleansing, and before any external fill is placed against the structure, it shall be filled to its overflow level at a rate approved by the structure manufacturer or as detailed in the Contract.
The water level shall then be recorded by an approved means for 3 days. The tank shall be deemed to have passed the test if there is no discernable change in water level after taking account of rainfall and evaporation, and that there are no visible signs of leakage from the walls or base of the structure.
This test shall only be carried out after a successful test of any roof structure.
Internal compartments shall be tested separately.
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