Atomic Energy authority

AIRFORCE (SLAF) HOSPITAL COLOMBO

Democratic Socialist Republic of Sri LankaDemocratic Socialist Republic of Sri Lanka

AIRFORCE (SLAF) HOSPITAL COLOMBO

Democratic Socialist Republic of Sri LankaDemocratic Socialist Republic of Sri Lanka

SRI LANKA AIRFORCE

AIRFORCE (SLAF) HOSPITAL COLOMBO

SECTION NO

[BUILDING CONSTRUCTION]

SECTION - PERTICULAR SPECIFICATIONS-CIVIL WORKS1. General

06

1.0 General

1.1 Temporary Services

1.2 Safety Measures and Health

1.3 Access to Site

1.4 Site Security

1.5 Programming of the works

1.6 Monthly Progress Reports

1.7 Construction Programme

1.8 Security Requirement

2. Facility for Engineers

092.1 General

2.2 Office for the Engineer(Off-site)

2.3 Office for the Engineer(On-site)

2.4 Laboratory and Equipments.

2.5 Survey Equipment and Assistant2.6 As-Built Drawings

3. Site Preparation, Mobilisation and Demobilisation

113.1 General

3.2 Site Preparation

3.3 Mobilisation

4. Site Clearing and Earth Works

134.1 Clearing and Grubbing4.2 Disposal of Cleared Material4.3 Disposal of Surplus Material4.4 Preservation of Property4.5 Earth Works4.6 Construction Method5. Concrete Works

15

5.1 General Requirements5.2 Material5.3 Concrete Mixes5.4 Ready Mix Concrete

5.5 Testing Works of Concrete5.6 Reinforcement5.7 Expansion Joints5.8 References6. Formwork

19

6.1 Construction of Formwork

6.2 Preparation of Formwork

6.3 Removal of Formwork

7. Reinforcement

20

7.1 Drawings

7.2 Cutting and Bending

7.3 Condition

7.4 Tying

7.5 Support of Reinforcement

7.6 Laps and Joints8. Block Work and Brick Works

21

8.1 General

8.2 Quality and Dimension

8.3 Manufacture of Blocks

8.4 Mortar

8.5 Workmanship9. Rubble Masonry Construction

23

9.1 General

9.2 Material

9.3 Construction Requirement

10. Waterproofing

24

10.1 General

10.2 Structure

10.3 Application

10.4 Water Proofing Systems to Roof Slab, Helipad and Other Areas.

10.5 Water Proofing Systems to Concrete Slab (Toilet,

Bath Rooms, Balcony and Gutters)

10.6 Water Proofing Systems to Sumps, Toilet and Ponds.

11. Steel for Roofs and Others

30

11.1 Roof Structure11.2 Roof Cover12. External Works

31

GENERAL SPECIFICATIONS

The works under this Contract shall be executed in accordance with the Specifications given in the following documents issued by the Institute for Construction Training and Development (ICTAD), Savsiripaya", Wijerama Mawatha, Colombo 07, as applicable. These shall be read in conjunction with the Particular Specifications given herewith and which shall take precedence over the ICTAD Specifications in the event of any ambiguity or discrepancy.

Publication No.

DescriptionSBD/04

Standard Bidding Document

Procument of Works (Design and Build)SCA/4 (Vol. I)

Specifications for Building Works

Vol. (I), Sri Lanka.

3rd Edition (Revised), July 2004

SCA/4 (Vol. II)

Specification for Building Works

Second Edition (Revised), October 2001

SCA/05(Vol. I)

Standard Specification for Construction and

Maintenance of Roads and Bridges.Note: Piling Specifications are given elsewhere.

Chapter 1General1.0General

This Specification shall be read in conjunction with the standard ICTAD Specification for Building Works. The standard ICTAD Specification and this Specification shall be treated as complementary documents. In case of any ambiguity or discrepancy between the standard ICTAD Specification and thisSpecification, shall prevail.

1.1Temporary Services

1.1.1The Contractor shall provide and maintain temporary services required such as power (including standby power) water and telephones etc. for the execution of the Works under the Contract unless otherwise specified as being provided by SLAF. The Contractor shall make applications and install such services in accordance with the regulations and requirements of the relevant authorities.

1.2Safety Measures and Health

1.2.1The Contractor shall provide and maintain the following safety measures in accordance with the regulations and requirements stipulated by the relevant Statutory Authorities.

a. Safe working conditions.

b. Safe means of access and exit.

c.Safety systems for Plant, Machinery and Equipment.

d. Appropriate safety equipment required at the site and yards such as Helmets, Boots, Masks, Goggles, Safety Belts, etc to the workmen and others engaged in the Works.

e.Safety nets, safety signs, handrails, platforms and other measures ensuring safety of workmen and others engaged in the Works.

f.

Training, instruction, information and supervision as may be required to enable employees to avoid any potential dangers and hazards.

g.All measures for protecting the health of workmen including satisfactory welfare facilities, working conditions and environment.

1.2.2Safety signs shall be in the Sinhala and English languages. Services of a suitable qualified and experienced Safety Officer shall be available at the site on a full time basis. A comprehensive First Aid Box shall be made available at the Site Office by the Contractor and he shall ensure that at least three of his staff is trained in firstaid measures. A vehicle suitable for transporting injured personnel shall be made available at the site by the Contractor. All costs in connection with safety and health mentioned above shall be borne by the.1.3Access to Site

1.3.1The Contractor shall organize and plan movement of materials and equipment to the site taking into consideration the factors affecting such movements in order to minimise delays and disruption to work.

1.4Site Security

1.4.1The Contractor shall be responsible for the security of his plant, equipment, materials etc. brought upon the site for the purpose of the works and shall provide fencing, shelters, watching, lighting etc, for the safety of such items. 1.5Programming of the Works

1.5.1The Contractor shall furnish in duplicate to SLAF the programme and particulars called for in the General Conditions of Contract. The programme shall show interalia. The dates of commencement and completion specified in the Contract.

The dates as determined or proposed for procurement, delivery to site of materials, commencement and completion of erection or installation of work in all trades.

The dates by which the Contractor requires information from SLAF.

1.6Monthly Progress Report1.6.1The Contractor shall submit to SLAF Employer not later than the 5th of every month a Progress Report for the previous month which shall include the following items and information:

The marked Programme submitted at the previous Monthly site Progress Meeting amended (if necessary) to indicate agreed revisions.

Summary of construction Plant onsite and offsite including dates of arrival and departure of items.

Summary of principal materials and manufacturers items placed on order and delivered to the sites.

1.7Construction Programme

1.7.1The following shall be considered when preparing the Programme and revisions due to constraints which may be experienced.

a. The necessity of multi-shift working and/or working during weekends or Public holidays.

b.Failure to consider the above implications, which are neither necessarily in the given order of priority nor to be considered as complete shall not entitle the Contractor to claim for additional time or extra costs whatsoever.

1.8Security Requirements

1.8.1The Contractor shall allow for ascertaining and complying with security authorities requirements and for all costs as necessary incurred in connection herewith. The Contractor shall also allow for requirements of the security staff of the SLAF.

Chapter 2

Facilities to be Provided and As-Built drawings2.1General

2.1.1Temporary buildings shall comprise proper sheds etc. for the storage, protection and safe keeping of materials, goods, tools etc. workshops for the preparation of works which are to be executed on-site; sheds and mess-rooms for the work people and for staff and all other offices and amenities in accordance with local Bye-laws, Acts and Regulations, for the Contractor and the Engineer.

2.1.2The Contractor shall provide and pay all charges for all air-conditioning, lighting, attendance etc. and shall allow for paying all rates and other charges which may be made by local or other authorities in connection with temporary areas and temporary buildings, necessary and erected or leased for the purposes of the Contract.

2.2Office for the Engineer (off-site)

2.2.1 The Contractor shall supply, erect on-site as well as off-site, maintain for the period of the Contract, and unless otherwise noted, remove upon completion of Contract, suitable offices for the Engineer and his staff.

2.3Offices for the Engineer (on-site)

2.3.1The on-site offices for the Engineer and his staff shall comprise of with basic requirements.2.3.2Other rooms required on-site, which may be used commonly (Engineer Contractor )

2.4

Laboratory and EquipmentsThe Contractor shall provide and maintain a laboratory and field testing equipment at site for testing of materials in accordance with the requirements in the Specifications and the directions of the Engineer.

2.5

Survey Equipment and AssistantDuring the period of the Contract, the Contractor shall provide and maintain for the sole use of the Engineer's Representative and his staff with surveying equipments for site at which work are being executed.2.6Safety Gear

The Contractor shall provide and maintain the safety gear for the Engineer's Representative and his staff during the execution of works. All above items shall be of a recognised brand and subject to approval of the Engineer's Representative.

2.7

As-Built Drawings

As soon as possible after completion of each as-built drawing, the Contractor shall deliver to the Engineer's Representative one pint of the drawing for checking. One additional print shall be provided on request, if the Engineer's Representative finds errors and wishes to mark up the drawing with necessary amendments. The Engineer will confirm acceptance of each drawing when satisfied that it correctly records the as-built details. At the end of the Contract, contractor will handover the as-built drawing (three sets of hard copy and one digital copy) to SLAF.

Chapter 3

Site Preparation, Mobilisation and Demobilisation

3.1

General

This chapter of the Specifications refers to certain particulars of the Contractor's general obligations under the Condition of Contract hereunder all temporary works, provisions of construction plants and equipment required for execution of the Works together with other temporary works and supplies specified in this section.On completion of the Contract, all temporary works, plants, equipment and surplus material shall be removed unless otherwise specified and the Contractor shall clean up all the premises of the Works.

3.2

Site Preparation

3.2.1General ViewApprox site area is 14,350 m with access to existing main road via side road on reserved site (see attached drawing: Site Plan). The erection of the side road outside the site boundaries and the preparation of all needed media connections (water, sewage, electricity, telecom, etc.) are excluded from the Contractors scope of work.

The site area is flat land. Existing trees and bushes on the site have to be rooted out where necessary. Main trenches for channels, (for building supplying services) potable water, fire fighting water, electricity etc. will be excavated and backfilled with the soil placed alongside the trenches. Electrical power supply cables will be protected with brick layer and warning tape.

Gardening and landscaping. Green areas around the buildings have to be covered with humus and planted with suitable grassing and some trees. Trees and bushes have to be planted according to the site-layout.

3.2.2Fence and access doors

The fence around the site has to be made of plastic coated galvanized mesh 1.80 m height. Manufacturing, fabrication and construction are based on the detail drawings. Site entering gates should be made out of steel and 6m x 1.8m in size manually operated according to the approved drawings.3.3Mobilisation

3.3.1Working Areas

The working areas include

A.The areas on which new structures shall be erected and their immediate vicinity. B.Areas for stockpiling of quarry stones and other building materials.

C.Areas for site offices, stores, garage and workshops and for the movement of the Contractor's equipment at Site.

Contractor may occupy working areas mentioned above at the commencement of the works and at no cost to him.

3.2.2Clearance of the Sites

The Contractor shall clear the working areas as necessary to carry out the construction. In order to preserve the vegetation the Contractor shall not be permitted to remove any trees unless approved by the Engineer's Representative and the respective landowner.

3.2.3Temporary Works

The Contractor shall provide, install and maintain all temporary offices, stores, workshops, labour camp, housing facilities for his staff together with all temporary roads, electricity supply, water supply, sanitary installations, telephone services and communication systems and other utilities required for the proper execution of the work.

3.2.4Plant and Equipment

Mobilisation of the Contractors constructional plant and equipment shall include:

a.Assembly, preparation and loading all plant and equipment at the Contractor's home station or source of supply.

b.Transportation of plant, equipment and material from the home station or source of supply to the site.

c.Unloading and installation of all plants and equipment ready for use.

Chapter 4Site Clearing and Earth Works4.1Clearing and GrubbingThis work shall consist of all clearing and grubbing required for the performance of the work covered by the Contract in accordance with this specification. Clearing shall consist of the removal and disposal of everything above ground level within the areas of earthworks as directed by the Engineer including overhanging branches. The material to be cleared shall include but not necessarily be limited to trees, stumps, logs, brush, undergrowth, grass, crops and loose-vegetable matter.

Grubbing shall consist of the removal and disposal of topsoil stumps and roots to a depth of at least 0.15m below ground level as indicated in drawings. In cut areas stumps and roots shall be removed to depths not less than 0.5 m below the top of the sub grade over which the pavement is to be constructed.

4.2 Disposal of Cleared Material

All un-saleable timber as designated by the Engineer and all stumps, roots, logs and other refuse form clearing and from the grubbing operations shall be disposed of by burning or other means approved by the Engineer. Piling of such material for burning shall be carried out, as approved by the Engineer, either at or near the centre of the cleared area or in adjacent open spaces where no damage to trees or other vegetation could occur.

Large stumps may be disposed of without burning at locations out of the area. In such cases The Contractor will be solely responsible for making the necessary arrangements and expenses arising form the use of private lands.

All burning shall be done in conformity with the regulations and at such times and in such manner as to prevent the fire from spreading to areas adjoining the right of way. The Contractor shall be responsible for damage to any property or injury to persons, resulting from such operations. At the end of such operations the area shall be left with a neat and finished appearance free of accumulations of burn or half burnt material.

4.3 Disposal of Surplus Material

Surplus excavated material shall not be discarded indiscriminately but shall be placed in spoil dumps to form neat and stable embankments in the areas shown on the drawings and such other areas as may be approved by the Engineer. Unless otherwise authorized by the Engineer, different types of surplus excavated materials shall be deposited separately in the spoil dumps and the upper surface and embankment slopes shall be trimmed to present a tidy appearance and to minimize erosion and pond of water.

4.4 Preservation of Property

Existing roadways, adjacent properties, utilities, services, trees and plants designated for preservation by the Engineer shall be protected form injury or damage which could result from the Contractors operation.4.5

Earth WorksThis work shall consist of all the excavation within the limits of the area. The work shall include hauling and stacking of suitable material, the disposal of unsuitable materials and trimming and shaping of exposed faces of excavation.

Contractor shall not dispose of surplus material by pushing it some other places of any excavation in sloping ground without the written consent of the Engineer.

4.6

Construction Method

All excavation shall be performed as specified herein and the completed area shall conform to the alignment, levels and grades given on the drawings and as required by the Engineer.

Where provided for on the drawing, topsoil encountered in excavation shall be removed to such a depth as the Engineer may direct. The topsoil shall be removed and sorted in the piles at locations designated by the Engineer.

Chapter 5Concrete Works5.1General Requirements

All material shall be in accordance with the standards stated in Clause 5.2 of these specifications. It is deemed that the Contractor has allowed for all charges for obtaining materials in conformance to these standards in the Bill of Quantities.

5.2Material5.2.1Cement

The cement used for all reinforced concrete works shall be Ordinary Portland cement complying with the requirements of SLS 107. All cement shall be supplied with proper certificates by the manufacturer and be complying with the requirements of the relevant standards.5.2.2Aggregates

Aggregates shall be in accordance with BS EN 12620:2002+Al:2008, 1192-2007 and 1200-2005 and tested in accordance with BS 812. All aggregates shall be hard, durable and clean, composed of inert material. 5.2.3

WaterWater used in mixing concrete, mortar, or grout shall be free from lime, sulphates or other deleterious materials and from a source approved by the Engineer. The Engineer shall have the right to require that samples of the water shall be subjected to analysis from time to time.

5.2.4

Admixtures

Admixtures may be used if approved and when so required. The plasticizer shall be transported to the Site under cover in sound and properly sealed bags or in the manufacturers containers, and shall be stored off the ground in a proper watertight shed of an approved design. The plasticizer shall be stored completely separated from all other materials to the approval of the Engineer.

5.3

Concrete Mixes

5.3.1

Grade designation

Grades of concrete shall be denoted by the 28 day test cube strength in Newtons per square millimetre (N/mm2).

5.3.2

Mix

Concrete mix shall be in accordance with Clause 5.3.3 and the grades approved appropriate to the work.

the Contractor shall submit the slump factor he proposes for approval before work commences. Neither trial mixes nor strength tests are required or prescribed mixes.

The concrete shall have sufficient workability to enable it to be placed and compacted by the methods used in.

5.3.3

Designed mix

The Contractor shall meet the requirements for the minimum cement content and other properties in his design mix. The Engineer may require to ensure durability etc. Designed mixes shall be in accordance with grades indicated in the drawings.5.3.4

Trial mixes

When designed mixes are specified, the trial mixes shall be prepared for each grade of concrete in accordance with the BS 1881-125:1986, BS 1881-129:1992 unless there are existing data showing that the proposed mix proportions and manufacture will produce a concrete of the strength and quality required having adequate workability for compaction by the method to be used in placing.5.3.5Workability

The workability of each batch of the trial mixes shall be determined by the slump test as described in BS 1881-103:1993 or by an alternative approved method.

5.4Ready Mixed Concrete

5.4.1Conditions for use

Subject to approval, the Contractor may use ready-mixed concrete in accordance with BS 1926. Approval shall be obtained for each proposed use of ready-mixed concrete in different sections of the works and for each different mix which shall comply with this specification.

5.4.2Curing Concrete

Concrete shall be protected against harmful effects of weather, running water and drying out. One of the following methods appropriated to the particular situation. A liquid curing compound shall be applied to the concrete surface by a low pressure spray until a continuous visible covering is achieved. The concrete surface shall be covered with Hessian, sacking, canvas or other absorbent material agreed by the Engineer. The concrete surface shall be covered with polyethylene sheets. If concrete surfaces which have become dry shall be thoroughly wetted before the sheeting is placed. The minimum curing period shall be seven (07) days.5.5

Testing Works of Concrete

5.5.1Sampling

Concrete shall be sampled in accordance with BS 1881-1993.

5.5.2

Workability

The workability of concrete shall be determined by the slump test as described in BS 1881-1993 or by an alternative approved method.

5.5.3Works cube tests

For each grade of concrete, 4 cubes shall be made from a single batch when required for each 15 m3 of concrete of part thereof in each day's work. The cubes shall be made, cured and tested in accordance with BS 1881-1993 or as otherwise approved. One shall be tested an age of 7 days and the other 3 at 28 days. Alternatively cubes may be tested in accordance with an approved accelerated testing regime. The Contractor shall submit certified copies of the results of all tests to the Engineer.

5.5.4Standard of acceptance

The standard of acceptance of the works cubes shall be in accordance with BS 8500-1-2002 or as otherwise approved. 5.6Reinforcement5.6.1GeneralThe type of reinforcement used in each part of the work shall as described on the drawings. All reinforcement used throughout the works shall be from one manufacturer.

Bars designated R shall be mild steel plain round bars having yield strength of 250N/mm2 complying with BS 8666:2005 and Bars designated T shall be high yield (deformed type 2) bars having yield strength of 460 N/mm2.5.6.2Welding of reinforcement

Welded joints and welding procedures shall be carried out in accordance with BS EN 1856-2:2004.5.7Applicable standards The following Standards and Codes of Practice are referred to in this specification and fully or partly incorporated herein as specified.DesignationTitle of Standards/Code of Practice

BS 12-1996(BS EN 197-1:2000)

Specification for Portland cement

BS 812 Part 2-1975,

(100-105, 109-111,

117, 119)

Methods of testing of aggregates

BS 882-1992(BS EN 12,620:2002)BS 1881-1998,

Parts 101-103,

106-120

Specification for aggregates from natural sources for concrete.

Methods for testing concrete

BS 3148-1980Methods of test for water for making concrete

BS 4449-2005Specification for carbon steel bars for the reinforcement of concrete

BS 8666:2005Specification for scheduling, dimensioning, bending and cutting steel reinforcement for concrete

BS 5075, Part 3:1985,Part 1-2: 1982Concrete admixtures

BS 8500-1-2002, BS 8500-2-2002Method of specifying Concrete mixers.

BS EN 197-1:2000Specification for Portland pulverised-fuel ash cement

BS 8110, Parts 1:1997, Part 2,3 : 1985Structural use of concrete

ASTM C 40-2004Organic impurities in fine aggregates for concrete

Chapter 6Formwork 6.1

Construction of Formwork

The Contractor shall be totally responsible for designing the formwork and supporting props required to construct the structure in accordance with the drawings. He shall submit drawings of his proposals to the Engineer for approval before the work is put in hand. Formwork shall be constructed from timber, steel or other approved materials such that the surface finish of the moulded concrete presents a smooth uniform face free from honeycombing, surface crazing or subsequent dusting. It shall be of sufficient strength and stability to safely support the wet concrete and any incidental loads which may be applied to the concrete surface before it has hardened. The maximum elastic deflection of any formwork component shall not exceed (1/500) th of its span.6.2

Preparation of Formwork

Before concrete is placed, the formwork shall be cleaned of all dirt and construction debris to the satisfaction of the Engineer. All surfaces shall be coated with approved mineral mould oil before concrete is placed and excess oil shall be removed.6.3

Removal of FormworkThe approval of the Engineer shall be required before the removal of any formwork. All formwork shall be removed without occurring damage to the concrete. The use of mould oil or other material to facilitate removal shall be subject to the approval of the Engineer.Chapter 7Reinforcement 7.1

Drawings

The Contractor shall supply and fix all reinforcement of diameters and shapes as shown on the drawings. In case reinforcement is not shown but when the nature and / or purpose of the relevant element distinctly and obviously required the incorporation of reinforcement, then The Contractor shall be deemed to have included in his tender a quantity of 120kg reinforcement per cubic meter of concrete for such elements.7.2

Cutting and BendingUnless shown to the contrary on the drawings, the cutting and bending of reinforcement shall be in accordance with the requirements of BS 8666. No steel which has been previously bent shall be re-shaped without the Engineers approval. 7.3

Condition

All reinforcement shall when placed be free from rust, scale, grease, clay, salt deposits and other coatings or deleterious material that would destroy or reduce the bond with the concrete and all reinforcement in store, on Site and in use shall be protected and/or cleaned as often as may be necessary.

7.4

Tying

All knots in tying wire shall be located within the reinforcement cage and shall not be located closer to the surface of finished concrete than the specified minimum cover.

Ensure that reinforcement cannot cause any rust staining to surfaces intended to be kept clean.

7.5

Support of Reinforcement

The Contractor shall supply and install chairs, ties, spacers, supports etc., as necessary to fix the reinforcement and maintain it in correct position during placing and vibration of concrete. Only precast concrete spacers shall be used in the formwork to maintain the required cover, their frequency and location shall be subject to the approval of the Engineer.

7.6

Laps and Joints

Laps and joints shall be in strict accordance with those specified on the Drawings. Relocation and additional laps shall be subject to the approval of the Engineer.Chapter 8Block Work and Brick Work 8.1General

Block work and Brickwork etc. described in this chapter applies to whole structure according to the Architectural and Structural drawings.

8.1.1All walls located at perimeter of the air-conditioned spaces shall be made of insulated cavity walls and should consist with; 100mm thick solid cement block for outer layer + 50mm thick insulation layer + 150mm thick hollow cement block for inner layer when walls are to be made as external walls.

100mmthick solid block for outer and inner layers + 50mm thick insulation layer when walls are to be made as internal walls.8.1.2Internal partition walls shall be 150m thick hollow block or 100 mm thick solid block work according to the Architectural and/ or Structural requirements. 8.1.3Walls in the bathroom areas shall be of 225mm thick brick work if its outside surface is exposed to a non air-conditioned area. If a bathroom wall is constructed at the perimeter of an air-conditioned zone, the inner layer of the cavity wall (layer at bathroom side) shall be of 115 mm thick brick work.

Internal walls of a bathroom area should be made with 115 mm thick brick works or water proofed partitioned according to the SLAF requirements.8.1.4 Proprietary type galvanised ties shall be used to connect two masonry leaf of cavity walls at specified spacings.

8.2Quality and Dimensions

8.2.1Concrete blocks (solid or hollow) for walls shall comply with BS 6073 Part 2: 2008.8.2.2Bricks, to be used for brickwork walls, shall be solid common clay bricks, complying with SLS 39: 1978(2008), and shall have an average compressive strength of not less than 5 N/mm2.8.2.3Nominal brick sizes shall be 225mm long, 115mm wide and 70mm thick.

8.2.4Nominal block sizes shall be 400mm long, 200mm high and 100mm, 150mm, 200mm thick, solid or hollow as indicated on the specifications and shall have an average compressive strength of not less than 5 N/mm2.

8.3Manufacture of Blocks

Blocks are to be manufactured in approved block-making machines from ordinary Portland cement and dense natural aggregates to BS 882: 1992, mixed as per BS 6073, Parts 2 :2008.8.4Mortar8.4.1Mortar for laying blocks and bricks shall consist of one part of Ordinary Portland Cement: five parts of sand and relevant admixtures to improve the workability.

8.4.2Ordinary Portland Cement for mortar shall comply in all respects with BS 12, 1978. Cement shall be delivered in the manufacturers original sealed bags and shall be stored in a proper manner to prevent deterioration.

8.4.3Sand for mortar shall be naturally occurring sand/approved sea sand or shall consist of crushed rock or gravel or a combination thereof with naturally occurring sand hard clean, free from adherent coatings. It shall comply in all respects with BS 1200, 1976 and be well graded from 5 mm down.

8.4.4Water for mortar shall be clean and free from acids, vegetable or other deleterious matter and comply with the requirements of BS 3148, 1980.

8.4.5No admixtures to mortar will be allowed without prior approval of the Engineer, but if allowed shall agree with the requirements of BS 4887 part 1, 1986.

8.4.6All material shall be obtained from approved sources of supply or approved suppliers. Cement mortar shall be used within two hours of mixing. Any mortar kept longer shall be discarded. Retempering or re-mixing of mortars is not permitted. All gauging, handling and mixing equipment shall be kept clean and free of deleterious materials. Mortar boards and other absorbent surfaces shall be dampened with clean water, and mortar not in use shall be covered in drying conditions.

8.5Workmanship

8.5.1Blocks shall be wetted as necessary prior to laying and kept wet for three days after in storage shall be protected from rain.

8.5.2All surfaces on which block work is to be built shall be clean. All block work shall be built uniform, true and level with all pretends vertical and in line.

8.5.3All walls shall be laid in stretcher bond unless otherwise indicated. Joints shall not be less than 10mm and not exceed 12mm.

8.5.4No damaged blocks shall be used and any non-standard sized blocks required to maintain bond shall be cut or sawn, true and even; in the case of hollow block walls from solid block.

8.5.5Newly laid block work shall be protected from the harmful effects of sunshine, rain, drying wind, running and surface water and shocks. Any work that is damaged shall be taken down and re-built or the joints raked out and pointed as directed by the Engineer. Costs incurred in carrying out such remedial works shall be borne by the Contractor. Scaffold boards shall be turned back during heavy rain and at night in order to minimise the possibility of staining the block work. All block work shall be kept clean. Rubbing or staining will not be allowed. Chapter 9

Rubble Masonry Construction

9.1General

This work shall consist of construction, in Random Rubble masonry walls, drains and other structures. Work shall be carried out to the lines and dimensions shown in the drawings or as directed by the engineer.

9.2Materials

Stones for rubble masonry shall be obtained from approved quarries, and be approved by the Engineer. They shall be hard, durable, fresh rock free from fractures and other imperfections and shall be of maximum dimension not exceeding 450 mm.

Unless otherwise specified the mix proportions for the mortar shall be 1 part of cement to 6 part of sand by volume.

9.3Construction Requirements

All stones used in rubble masonry shall be cleaned before use to ensure clean surfaces to facilitate adherence of mortar to them and shall be wetted before laying. Every stone shall be set flush in cement mortar of 1:6 or any other approved mix proportions, and there shall be no dry work or hollow spaces left. The stones shall be laid to roughly fit the spaces between the larger stones and ships and spalls shall be wedged in where necessary to prevent thick beds of mortar. The face joints may vary in thickness from 16 mm to 40 mm. Small stones shall be carefully selected to roughly fit the spaces between the larger ones. Chips and spalls shall be wedged into the work where necessary to prevent thick beds of mortar.

The top surface of rubble masonry shall be finished with mortar topping as directed by the Engineer. All rubble masonry work shall be maintained in constantly wet condition for a period of at least 3 days commencing from the time of final setting of the cement.

Chapter 10

Waterproofing 10.1

General

10.1.1

Insulation and water proofing shall be applied in accordance with the directions of the manufacturer of the materials and components, and the complete systems shall be fitted in the works by experienced specialist crew.

10.1.2

Notwithstanding maintenance requirements for the works, the Contractor shall warrant the SLAFr with the assurance of a reputable local insurance company that roofs, walls of source well, basement and toilets shall remain waterproof, vapour proof and damp-proof in respect of workmanship and materials for a minimum period of 10 years calculated from the time that the works are certified as substantially completed.

10.1.3

The form of guarantee offered by the specialist, applicator shall be submitted for the Engineer's approval prior to commencement of waterproofing. This guarantee shall in no way indemnify against the improper performance of the waterproofing system.

10.1.4

All structural components that retained or exclude water or any other liquid should be applied with approved water proofing material.

10.1.5

Roof slabs should be externally water proofed and insulated by an agent approved by the Consultant.

10.2.

Structure

10.2.1

It shall be the Contractor's responsibility to ensure that the specialist applicator takes note of the type of the structure, nature and the location of waterproofing to be applied, including any movement joints provided, when designing his water proofing system.

10.2.2

The laying of a water proofing system on a concrete surface will be taken as signifying the acceptance of that surface, both in terms of surface quality, spacing and arrangement of movement joints and the construction joints by the Contractor and his specialist applicator.

10.3

Application

10.3.1

Where applicable, toilets, bathrooms, helipad area and roof slabs shall be incorporated, corrected finished and uniformly lined.

10.3.2

The water proofing system shall be dressed up all pipes and other penetrations to a minimum height of 250 above the top of the concrete slab.

10.3.3

Sharp corners are to be filled with screed or other fillets and water proofing should be laid with generous over lap as per manufacturer's instructions.

10.3.4

When water proofing is to be applied on exposed areas, colours have to be approved by the Engineer.

10.3.5

Where finishes such as concrete paving or tiles are specified and to be laid over water proofing membrane of concrete floor, the floor shall be tested for water - tightness prior to laying of these tiles/paving. The structures such as source well shall also be tested after the application of water proofing systems. The cost of carrying out these tests including that of blocking any outlets shall be borne by the Contractor. Where it is seen that water tightness has not been achieved, the Contractor shall take whatever remedial measures as are ordered by the Engineer and the cost of all such measures shall be borne by the Contractor.

10.4Waterproofing System to Roof Slab, Helipad and other areas (WP1)

10.4.1 Levelling screed (Rendering)10.4.1.1Before laying the levelling screed, the concrete surface shall be cleaned by removal of loose materials to the entire satisfaction of the Consultant. Concrete which is contaminated by oil or grease shall be chiselled away and refilled.

10.4.1.2Concrete slab shall be grouted with a cement / water slurry before the laying of levelling screed.

10.4.1.3 1:3 cement: sand levelling screed shall be mechanically batch mixed and laid with a minimum thickness of 25mm; the falls to be achieved are not less than 1:200 or as shown on the drawings. Screeds shall be laid with even slopes and internal and external corners shall have cover fillets with a radius of at least 70mm. The screed shall be finished with a wooden float.

10.4.1.4 The screed shall be covered with wet saw dust, sand or equal method and kept damp for 5 days, or as ordered by the Consultant. Screed shall be protected from rainfall. Waterproofing membrane shall not be applied until the surface is thoroughly dried out.

10.4.2

Water proofing (WP1)

10.4.2.1Material Specification Torch-On Waterproofing Membrane.

10.4.2.2The following specification is for a built-up Waterproofing system of non-metallic roofing compound of laminar bituminised construction, intended for this project. The Contractor may submit alternative reputable constructions together with the relevant specification and method statement to the approval of the Consultant; such constructions should in any case conform to the insurance requirement specified under "Warranty" requirement.

10.4.2.3Waterproofing membrane shall be 4.0mm thick with sand finish on top, UV resistant;

Atactic Polypropylene (APP) modified bituminous membrane reinforced with 160g/m2 polyester fabric, with approximate weight 4.6 kg/m2 and torch-applied over the substrate after application of the approved primer.

10.4.2.4An interruption of work the edges of the sheets have to be finished in such a manner that rain water and dust cannot penetrate underneath.

10.4.2.5 A Prefabricated multi-layer sandwich type membrane should conform to the manufacturers Specifications.

10.4.3Insulation for roof slab10.4.3.1On top of the Waterproofing membrane, polyurethane or equivalent extruded polystyrene boards 25-50mm thick with Thermal conductivity of not more than 0.03W/Mk (as per ASTM C5 18) shall be laid.

10.4.3.2Method should comply with the following standards ASTM D-1622, ASTM C-518, ASTMD2842 and ASTM D1621-95.

10.4.3.3The boards shall have rebated / ship lap edges all round for interlocked laying in sizes of 600x1200mm, tightly laid in stretcher bond.

10.4.3.4The compressive strength of the insulation boards shall be not less than 40kPa according to ASTMC165 procedure B.

10.4.3.5

Insulation boards shall be protected against rain and humidity.

10.4.4

Separation layer

10.4.4.1On top of the insulation / waterproofing membrane, non-woven geo-textile polyester mat or equivalent shall be laid as the separation layer.

10.4.4.2

It should conform to the manufacturer's specifications.

10.4.5Concrete covering screed

10.4.5.1Concrete covering screed of grade 20-25mm thick shall be laid over the gauge 1000 polythene sheet (Separation sheet) as shown on the drawing. 50 x 50mm (3mm dia.) galvanized steel wire-mesh shall be incorporated in the concrete screed layer. 10mm thick expansion joints shall be provided in covering screed to limit the concrete screed panel size approximately to 4.0 Sq.m. Expansion joints shall be coincided with the joints of the tile layer (if any) above and later filled by the approved joint sealant (DOW CORNING 790 SILICONE BUILDING SEALANT).

10.4.5.2Floor tiles with approved colour and quality shall be laid over the screed as the finishing layer,

10.4.5.3Alternatively Reinforced concrete floating slab shall be constructed instead of concrete screed if there is any possibility of installation of mechanical plants or equipment.

10.5

Waterproofing System to Concrete Slabs (Toilets, Bath rooms, Balcony, Gutters) before finishing (WP2)10.5.1

General

10.5.1.1This Chapter describes the water proofing of interior as well as exterior concrete slabs before receiving the ultimate finish such as screed, screed with tiling, screed with masonry slabs, asphaltic concrete etc.

10.5.1.2Waterproofing shall be carried out in specified area of the concrete floor slab and up to 300mm minimum and 2m in shower areas above the finished floor level or water level on masonry walls.

10.5.2Certificate and warrantee10.5.2.1The Contractor shall submit jointly prior to acceptance of the work, written certificate stating that all materials and workmanship in connection with specified work have been furnished and installed in completed conformance with these specifications and with the approved manufacturer's requirements for this work.

10.5.2.2 The Contractor shall jointly with the manufacturer/supplier of the specialist waterproofing material furnish a warranty to the Employer valid for a period of 10 year after handing over of the work, against dampness and/or moisture penetration through treated surfaces due to defective material and/or defective workmanship.

10.5.2.3 The warranty shall provide not only the materials necessary to remedy a problem but also the labour and equipment to apply the material.

10.5.3

Surface preparation

10.5.3.1The floor slab shall be thoroughly washed and cleaned to be free of loose mortar particles, paints, films, damp, laitance, dust and dirt etc. and if contaminated by oil or grease of whatever nature, the patches shall be chiselled away.

10.5.3.2Uneven areas, rough areas and chiselled patches to be treaded with an approved epoxy-resin based un-pigmented primer, and to be levelled with a homogeneously mixed approved 2-component epoxy-mortar, applied while the primer is not fully hardened (wet-in-wet-method).

10.5.3.3The smoothness and evenness of the surfaces of concrete to which the water proofing system is to be applied shall be to the entire satisfaction of the Consultant.

10.5.3.4The primer shall be a cement paste (cement + water + resin dispersion) applied as a grouting for key of the mortar. The mortar shall consist of cement + sand + resin dispersion. The compressive strength of the fully hardened mortar shall not be less than 20 N/mm.

10.5.3.5Both primer and mortar shall be of an approved make and be mixed and applied in strict accordance with the manufacturer's instructions.

10.5.3.6The mortar to be finished smooth and straight using steel floats in a rotating movement and under even pressure, with rounded or covered fillets/edges as the position or purpose dictates.

10.5.3.7Cement/sand (1:3) mortar plaster 6-15mm thick shall be applied to masonry wall and form motor fillet at slab/wall joint.

10.5.3.8The waterproofing liquid membrane shall be applied on the dampened screed surface and up to 300mm minimum on the cement/sand backing of masonry wall in conformity with the water proofing material supplier/manufacturer's printed literature and under the direction of supplier/manufacturer's representative10.5.3.9After the waterproofing membrane is sufficiently cured the relevant area shall be ponded with water for at least 3 days for observation of leaks.

10.5.3.10A cement sand (1:3) screed shall be laid soon after the water test is completed, taking care not to disturbed or damage the waterproofing application in any way. For the areas ceramic floor tiling to be done, cement sand screed (tile bed) shall immediately follow the water testing using this as the backing. Other areas shall be finished smooth with neat cement.

10.5.4

Waterproofing

10.5.4.1Material Specification-Flexible Cementitious Coating System

10.5.4.2The material used shall 2 part polymer (acrylic), flexible cementations waterproofing slurry or equivalent to 1.5mm minimum thickness with sound bond properties to cement screed/mortar surfaces.

10.5.4.3Water proofing of concrete slabs before receiving the ultimate finish shall be carried out as detailed below.

10.5.4.4In these areas, the prepared concrete floor and abutting up-stands/fillets shall be water proofed by means of application of Polymer modified cementations water proofing coatings or other approved method in accordance with the manufacturers instruction.

10.5.4.5The water proofing system shall be applied in strict accordance with the manufacturer's instructions, including primers etc. The system shall be suitable to receive the screed.

10.5.4.6The Contractor shall ensure that all penetrations of the relevant floors/slabs shall be water proofed in a workmanlike manner and as per instructions by the manufacturers or, lacking that, by the Engineer.

10.5.4.7The Contractor shall ensure timely submission to the Engineer of details, type, make and composition of the systems, together with certified proof from the manufacturer in respect of the suitability of his system.

10.6

Waterproofing System to Sumps, Tanks and Ponds (WP3)10.6.1

General

10.6.1.1Internal of Floors and walls of all sumps and tanks shall be coated with Polymer modified cementation water proofing coatings. The method of application and quality of material shall be to the approval of the Engineer.

10.6.1.2The surfaces to receive the water proofing shall be smooth, free from dust and dirt. Splayed or rounded fillets shall be provided between horizontal and vertical surfaces and at all junctions of vertical or horizontal surfaces.

10.6.1.3The joints in each application shall overlap one another and shall not coincide with the joints in previous coats.

10.6.1.4The Contractor shall ensure that the coatings are not damaged in any way and will provide protection at all times during the execution of the Works.

10.6.2

Waterproofing

10.6.2.1

General

10.6.2.1Material Specification-Cementitious coating system.

10.6.2.2The water proofing shall consist of application of Polymer modified cementitious approved water proofing coating according to the manufacturers recommendations.

10.6.2.3The Contractors shall ensure that all penetrations for piping, gulleys etc., shall be water proofed in a workmanlike manner.

10.6.2.4The Contractor shall satisfy the Engineer that the waterproof coating is not of a toxic nature, giving no elements toxic to drinking water.

10.6.2.5If the latter should occur, the Contractor shall provide and apply extra coat(s) of non-toxic sealant to walls and floors of drinking water sumps, all in accordance with the manufacturers' instructions.

Chapter 11

11.0 Steel Roof Construction 11.1

General

Curved shape steel roof shall consist of Aluminium/Zinc Alloy coated steel claddings and insulation layer supported on galvanized steel C purling and steel trusses. Roof cladding, purling and roof trusses shall be designed for self weight, imposed load and wind loads. The design of roof shall be done in such way to facilitate the rain water harvesting required according to the local regulations. The slope and the profile shall be selected to facilitate the effective drainage of the roof to the gutters which are connected to the rainwater sump.

11.2

Steel Trusses

Mild steel trusses shall be designed and installed by the Contractor for the curved roof. Contractor shall submit the design calculations and shop drawings for the roof structure with all fixing details for the Engineers approval.

Roof trusses shall be made out of mild steel circular tubes Grade 43 according to BS 4360 and bolts to be Grade 4.6 according to BS 5950. After fabrication, the truss shall be hot dipped galvanized according to the BS 729. Any connection which will be fixed after galvanizing shall be bolt connection. No drilling or welding shall be allowed after galvanizing. After welding the trusses shall be painted with approved colour. Acid-etch of mordant solution or acid containing etching primer shall be used prior to painting to enhance adhesion of surface coatings.

Welding electrodes shall comply with BS 639 and structural steel shall comply with BS 4360. Electrode strength E43 on grade 43 steel shall be 215 N/mm2. All members shall be welded along the full length of the perimeter of the connecting plates at welded joints. Unless otherwise indicated all welding should be with 5 mm of leg length having strength of 0.75 kN/mm2 .

11.3

Purlins

Purlins are COLD formed from hot dipped zinc coated high strength steel strip which has minimum yield stress of 450 MPa. The standard galvanized coating is 450g/m to BS 2989 on all sides. Minimum thickness of purlins shall be 2.0 mm. C sections shall be used for simple span construction with the purlin butted at internal support.

11.4

Insulation

Insulation shall be 100 mm thick glass fibre of 24 kg/m3 density having thermal conductivity of less than 0.035W/mK at mean temperature 25 C0, thermal resistance (R value) shall be greater than 2.857 m2/WC0 laid on two way reinforced double sided aluminium foil.

All joints shall be sealed with aluminium vapour sealed tape and thermal insulation system shall be supported with a 3x3 17 gauge BRC welded roofing galvanized mesh fixed to the purlins.

11.5

Roof covering

Roof cladding shall be pre-painted steel complying with AS/NZS 2728:1997. The coated steel shall comply with AS 1397-2001. Minimum yield strengths shall be G550 (550 MPa) and minimum coating mass shall be AZ 200(200 g/m2). The maximum recommended support spacing shall be based on testing in accordance with AS 1562.1-1992. The resistance to concentrated loads of roof claddings shall be tested in accordance with AS4040.1-1992.

Chapter 12

External Works

(Roads, Ramps, Vehicle Parking Areas and Storm Water Drainage Works)

12.0

General

The works described in this chapter shall be applicable for internal roads, vehicle parking areas, elevated vehicle access roads / ramps and storm water drainage works. The works shall be carried out according to the Standard Specification for Construction and Maintenance of Roads and Bridges, published by ICTAD unless otherwise stated differently in this specifications.Pavement structure of internal roads, ramps and parking areas constructed on the ground shall consist of subgrade, base and wearing course. Subgrade shall be constructed with good quality gravely soils with minimum thickness of 500mm while pavement base course shall be constructed with ABC material having minimum thickness of 300mm. The wearing surface shall consist of 50mm thick asphalt concrete over the base course.

Roads, ramps and parking areas constructed on concrete slabs shall consist of 50mm thick asphalt concrete wearing course on approved waterproofing layer.

12.1

Preparation of Sub grade

12.1.1

Material

Soil used for the construction of subgrade should be Type I material, having following characteristics.

Maximum dry density under standard conditions as determined by the Standard Proctor Compaction Test as described in BS 1377 not less than 1600 kg/m3.

The 4 day soaked CBR of the soil 100 % maximum dry density under standard conditions of compaction shall not less than 15 %.

The PI and LL of the soil shall be less than 15% and 40 % respectively.

12.1.2

Method of Construction

The material shall normally be placed in layers not exceeding 225 mm loose thickness, for compaction using 8-10 ton smooth wheeled roller or any other roller of comparable compactive effort to density not less than 98% of the maximum dry density. The compaction shall be carried out at or near the optimum moisture content. Rolling shall commence at the edge and proceed towards the centre longitudinally except at super elevated sections where the rolling shall commence at the lower edge and proceed towards the higher edge.

12.2

Formation of Pavement Base

12.2.1

Material

The material shall be crushed rock with nominal maximum size of 37.5(40) mm conforming to following requirement.

The aggregate Impact value (AIV) shall not been greater than 30 %.

The Flakiness Index shall not be grater than 35 %

12.2.2

Method of Construction

The aggregate shall be spread without segregation over the prepared surface of subgrade and shall be ensured that the thickness of each shall not be less than 75 mm and not exceed 150 mm. In order to reduce segregation material shall be kept wet during transporting and spreading. Sufficient water shall be added to facilitate compaction and the base material shall be compacted using a 8-10 ton roller and density shall be not less than 100% of maximum dry density as determine by the standard compaction test.

12.3

Laying of Asphalt Concrete Wearing Surface.

12.3.1

Materials

Bitumen

Materials used shall conform to the requirements of the following unless otherwise specified. The bitumen binder shall be 80 100 penetration grade bitumen. It shall conform to the requirements given in following Table.

Requirements of 80 100 Penetration Grade Bitumen

Penetration 25C, 100 gm 5 secs. 1/10mm80 - 100

Softening point C47 55

Loss on heating for 5 hrs. at 163C

(a)Loss in weight percentnot greater than 0.5

(b)Loss in penetration, percent of original valuenot less that 80

Solubility in carbon disulphide or carbon tetrachloride or trichloroethylene, percentnot less than 99.5

Flash point (Cleveland open cup) Cnot less than 232

Aggregate

(i)Coarse Aggregate

The coarse aggregate of nominal maximum size 19mm shall also conform to the following requirements:

The Aggregate Impact Value (AIV) shall not be greater than 30%.

The Los Angeles Abrasion Value (LAAV) shall not be greater than 40%.

The Flakiness Index (FI) shall not be greater than 35%.

(ii)Fine Aggregate

Fine aggregate (aggregate substantially passing the 4.75m sieve) used for surfacing shall either be crusher fines or river sand.

(iii)Filler

Filler, where separately used in the mix, shall be cement, hydrated lime, crusher fines or any other non plastic inert material approved by the engineer.

12.3.2

Construction Method

Preparation of Surface

When asphaltic concrete are laid over aggregate bases, prior to construction, the surface shall be cleaned for extraneous matter and applied with a prime coat using CSS-1 emulsion at a rate of 1 L/m2.

Transport of Mix accordance with the Clause 506.5 (f) of Standard Specification for Construction and Maintenance of Roads and Bridges unless otherwise specified.

Compaction Procedure

Immediately after the mix had been spread as struck off, the surface shall be checked and any irregularities adjusted. Rolling shall commence as soon as the material will support the roller without undue displacement or cracking.

The density of all samples taken from the compacted surface course shall be in between 96% to 98% of the Marshall Density at the point appropriate to the locations.

Joints

Both longitudinal and transverse joints in successive courses shall be staggered so as not to be one above the other. As far as practicable, longitudinal joints shall be arranged so that the joints in the top course shall be at the location of the line dividing the traffic lanes, and the transverse joints shall be staggered at a minimum of 250mm and be straight.

Longitudinal and transverse joints shall be made in a careful meaner so that well bonded sealed joints are provided for the full depth of the course. No mixture shall be placed against previously rolled material unless the edge is trimmed vertically to line and the vertical edge applied with a very thin coating of binder just before additional mix is placed against the previously compacted material.

Paving shall be as nearly continuous as possible and rollers shall pass over the unprotected end of freshly load mix only when authorized by the Engineer. In all such cases provision shall be made for a properly bonded and sealed joined with the new surface for the full depth of the course as specified above. Before placing mix against them, all contact surfaces of kerbs, gutters, manholes, etc. shall be given a thin uniform coating of his bitumen and the joints between this structure and the surface mix shall be effectively sealed by the subsequent spreading, fishing and compaction operations.

12.4

Storm Water Drainage System

The Contractor shall design and construct underground storm water drainage system for the entire site. In the design the Contractor shall assumed appropriate rainfall data for the location of the site and the drainage system shall be designed for 25 years return period. The drainage system shall comprise of proprietary type of cast iron or galvanized steel gratings, reinforced concrete catch pits, manholes etc. and reinforced concrete pipes for underground drainage system. All structures and underground pipes shall be constructed with grade 35 concrete reinforced to cater with soil pressures and maximum possible traffic loads. All gratings and manhole covers shall be designed for maximum possible traffic loads.

Democratic Socialist Republic of Sri Lanka

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Democratic Socialist Republic of Sri Lanka

CECB DEC Page 34