csp003 - concrete rev.1.pdf

PT. INTERNATIONAL NICKEL INDONESIA Specification Number CSP003 rev.1 Concrete Specification, Installation and Finishing

CSP - 003 CONCRETE SPECIFICATION,

INSTALLATION AND FINISHING

Release for construction Issue Date Description

Prepared Reviewed

(Technical) Reviewed MGR C/M CE

Approved GM Central Eng.

TABLE OF CONTENTS

NO. DESCRIPTION PAGE

1. SCOPE 4 2. CODE AND STANDARD 4 3 DEFINITION 4 4. QUALITY CONTROL AND ASSURANCE 8 5. GRADES OF CONCRETE

5.1 Testing 5.1.1 General 5.1.2 Slump 5.1.3 Acceptance Criteria

8 9 9 9 10

6. ACCEPTABILITY OF CONCRETE 6.1 Materials 6.1.1 Concrete mix 6.1.2 Aggregates 6.1.3 Admixtures 6.1.4 Steel reinforcement 6.1.5 Storage of Materials 6.1.6 Mixing and delivery 6.2 Mix acceptance 6.2.1 Approved mix 6.2.2 Variation of approved mix 6.3 Admixtures 6.3.1 Water-reducing 6.3.2 Superplasticiser 6.3.3 Accelerator admixtures 6.3.4 Retarder 6.3.5 Other admixtures

10 10 10 11 11 12 12 12 14 14 14 14 14 14 15 15 15

7 INSTALLATION OF CONCRETE AND RELATED WORK 7.1 Formwork

7.1.1 Materials 7.1.2 Construction 7.1.3 Coating 7.1.4 Removing bracing and Shoring

7.2 Steel reinforcing 7.3 Preparation 7.4 Placing of concrete 7.5 Curing 7.6 Membrane curing 7.7 Weather protection 7.8 Finishing concrete surface 7.9 Joints

7.9.1 Construction Joints 7.9.2 Expansion Joints 7.9.3 Control Joins 7.9.4 Joint sealer

7.10 Grouting

15 15 15 15 16 16 16 17 18 19 19 20 20 22 22 23 24 25 25

8 SLAB FINISHES 25


3

8.1 Un-formed finish 8.2 Formed finish 8.3 Finishing tolerance

25 28 28

9 REJECTION 28 10 STATEMENT OF COMPLIANCE 30


4

1.0 SCOPE

1.1 This specification applies to the furnishing and installation of concrete and related work in accordance with the contract drawings and this specification. All drawings and other referenced documents are included in this specification.

1.2 Work performed under this specification will be subject to the approval of the ENGINEERING DEPARTMENTS duly authorized representative hereinafter referred to as THE ENGINEER.

1.3 Any aspects of the work not clearly defined by this specification shall be governed by the rules of the best prevailing practice for that class of work as determined by THE ENGINEER.

1.4 Also included shall be the provision of all holes, chases, slots, etc., required for pipe and other work, and filling in of all such openings that are of a temporary nature, and the setting of anchor bolts, inserts, hangers, etc., required by others.

2.0 CODES AND STANDARDS

All aspects of concrete installation method and specification including, but not limited to those listed above, shall be in accordance with the provisions of the following standards;

AS 1012 (1993) : Methods of testing concrete AS 1379 (2007) : Specification and supply of concrete AS 3600 (2001) : Concrete structures AS 1478 (2000) : Chemical admixtures for concrete, mortar and grout AS/NZS 3905 (1999) : Quality system guidelines AS 3972(1997) : Portland and blended cements AS 3610 (1995) : Formwork for concrete

Note: 1. Additional standards are also referenced within the above standards. 2. The above standards are current at the time of drafting this specification, and may be

revised/superseded/supplemented without revision to this listing.

3.0 DEFINITION Admixturematerial, other than water, aggregate, and hydraulic cement, used as an ingredient of concrete, mortar, grout, or plaster and added to the batch immediately before or during mixing. Aggregategranular mineral material such as natural sand, manufactured sand, gravel, crushed stone, air-cooled blast-furnace slag, vermiculite, or perlite.


5

Air contenttotal volume of air voids, both entrained and entrapped, in cement paste, mortar, or concrete. Entrained air adds to the durability of hardened mortar Batchingprocess of weighing or volumetrically measuring and introducing into the mixer, the ingredients for a batch of concrete, mortar, grout, or plaster. Bleedingflow of mixing water from a newly placed concrete mixture caused by the settlement of the solid materials in the mixture. Coarse aggregatenatural gravel, crushed stone, or iron blast-furnace slag, usually larger than 5 mm (0.2 in.) and commonly ranging in size between 9.5 mm and 37.5 mm (38 in. to 112 in.). Compressive strengthmaximum resistance that a concrete, mortar, or grout specimen will sustain when loaded axially in compression in a testing machine at a specified rate; usually expressed as force per unit of cross sectional area, such as megapascals (Mpa) or pounds per square inch (psi). Concretemixture of binding materials and coarse and fine aggregates. Portland cement and water are commonly used as the binding medium for normal concrete mixtures, but may also contain pozzolans, slag, and/or chemical admixtures. Construction jointa stopping place in the process of construction. A true construction joint allows for bond between new concrete and existing concrete and permits no movement. In structural applications their location must be determined by the structural engineer. In slab on grade applications, construction joints are often located at contraction (control) joint locations and are constructed to allow movement and perform as contraction joints. Contraction jointweakened plane to control cracking due to volume change in a concrete structure. Joint may be grooved, sawed, or formed. Also known as a Control joint. Corrosiondeterioration of metal by chemical, electrochemical, or electrolytic reaction. Construction Manager The construction manager (CM) is a professional management person/ organization employed by the owner to oversee and manage the project. During the construction phase, the CM will oversee the work and perform many of the coordination functions of the general contractor. Curingprocess of maintaining freshly placed concrete mortar, grout, or plaster moist and at a favorable temperature for a suitable period of time during its early stages so that the desired properties of the material can develop. Curing assures satisfactory hydration and hardening of the cementitious materials. Damp proofingtreatment of concrete, mortar, grout, or plaster to retard the passage, or absorption of water, or water vapor. Densitymass per unit volume; the weight per unit volume in air, expressed, for example, in kg/m3 (lb/ft3).


6

Durabilityability of Portland cement concrete, mortar, grout, or plaster to resist weathering action and other conditions of service, such as chemical attack, freezing and thawing, and abrasion. Engineer The engineer is responsible for the detailed design for the concrete design portions of the project. As part of this process, the engineer develops detailed structural concrete contract documents and specifications. Other important functions of the Engineer are to review concrete and rebar schedule drawings for consistency with the design intent and to review the structural assembly during the construction phase. The engineer may be either an employee of the primary architectural and engineering firm, or an employee of an outside consulting firm, or of the owner. Engineering departments Department lies under PT INCO Tbk organizational breakdown structure. Epoxy resinclass of organic chemical bonding systems used in the preparation of special coatings or adhesives for concrete or masonry or as binders in epoxy-resin mortars and concretes. Expansion jointa separation provided between adjoining parts of a structure to allow movement. Finishingmechanical operations like screeding, consolidating, floating, troweling, or texturing that establish the final appearance of any concrete surface. Formworkstemporary supports for keeping fresh concrete in place until it has hardened to such a degree as to be self supporting (when the structure is able to support its dead load). Freeze-thaw resistanceability of concrete to withstand cycles of freezing and thawing. (See also Air entrainment and Air-entraining admixture.) Groutmixture of cementitious material with or without aggregate or admixtures to which sufficient water is added to produce a pouring or pumping consistency without segregation of the constituent materials. Honeycombterm that describes the failure of mortar to completely surround coarse aggregates in concrete, leaving empty spaces (voids) between them. Hydrationin concrete, mortar, grout, and plaster, the chemical reaction between hydraulic cement and water in which new compounds with strength-producing properties are formed. Isolation Jointseparation that allows adjoining parts of a structure to move freely to one another, both horizontally and vertically. Jointsee Construction joint, Contraction joint, Isolation joint, and Expansion joint.


7

Limegeneral term that includes the various chemical and physical forms of quicklime, hydrated lime, and hydraulic lime. It may be high-calcium, magnesian, or dolomitic. Mortarmixture of cementitious materials, fine aggregate, and water, which may contain admixtures, and is usually, used to bond masonry units. Pavement (concrete)highway, road, street, path, or parking lot surfaced with concrete. Although typically applied to surfaces that are used for travel, the term also applies to storage areas and playgrounds. Plasticizeradmixture that increases the plasticity of portland cement concrete, mortar, grout, or plaster. Portland cementCalcium silicate hydraulic cement produced by pulverizing portland-cement clinker, and usually containing calcium sulfate and other compounds. Portland-pozzolan cementhydraulic cement consisting of an intimate and uniform blend of Portland cement or portland blast-furnace slag cement and fine pozzolan produced by intergrinding portland cement clinker and pozzolan, by blending portland cement or portland blast-furnace slag cement and finely divided pozzolan, or a combination of intergrinding and blending, in which the amount Precast concreteconcrete cast in forms in a controlled environment and allowed to achieve a specified strength prior to placement on location. PTI Representative He/She that has the responsibilities to sign for approval and/or acknowledge for related project as per matrix responsibilities and organizational breakdown structures inside the PTI project. Quality controlan action taken by a producer or contractor to provide control over what is being done and what is being provided so that applicable standards of good practice for the work are followed. Ready-mixed concreteconcrete manufactured for delivery to a location in a fresh state Reinforced concreteconcrete to which tensile bearing materials such as steel rods or metal wires are added for tensile strength. Retarderan admixture that delays the setting and hardening of concrete. Scalingdisintegration and flaking of a hardened concrete surface, frequently due to repeated freeze thaw cycles and application of deicing chemicals. Segregationseparation of the components (aggregates and mortar) of fresh concrete, resulting in a nonuniform mixture. Setthe degree to which fresh concrete has lost its plasticity and hardened.


8

Shrinkagedecrease in either length or volume of a material resulting from changes in moisture content, temperature, or chemical changes. Slumpmeasure of the consistency of freshly mixed concrete, equal to the immediate subsidence of a specimen molded with a standard slump cone. Superplasticizer (plasticizer)admixture that increases the flowability of a fresh concrete mixture. Water to cement ratio (water-cement ratio and w/c)ratio of mass of water to mass of cement in concrete. Water reduceradmixture whose properties permit a reduction of water required to produce a concrete mix of a certain slump, reduce water-cement ratio, reduce cement content, or increase slump.

4.0 QUALITY CONTROL AND ASSURANCE

The contractor shall implement and maintain an approved quality control/quality assurance system covering all testing and manufacturing equipments, materials and workmanship used in the manufacture of the concrete. Approved quality assurance and control system shall as minimum, comply with the requirements of the PTI project team. Proof of a certified quality assurance system shall be provided to project team before production of concrete to this standard commences. PTI representative may carry out a quality audit of the contractor quality system when required. Contractor shall provide the PTI project team representative access to the contractor quality procedures and records to enable monitoring and quality auditing at all times during construction stages Random sampling and/or testing will also be carried out on the job site. Auditing and proof testing by PTI representative shall in no way relieve the contractor of any of the obligations under this standard specification.

5.0 GRADES OF CONCRETE

Concrete shall be in accordance with AS 1379 except where specified otherwise in the project drawing. Drawing in this specification refers to the Release for Construction (RFC) drawing that has been signed by PTI representative and attached in the project contract document. Slump tolerance as shown in table 5.1 indicates value contactor shall obtain during concrete testing as per RFC drawing specification. Concrete application for normal concrete made with Portland Cement Type I or Type II shall be used for interior walls, slabs, and foundations. High early strength concrete when used shall be made with Portland Cement Type III.


9

Table 5.1 Grades of concrete( for basic concrete strength)

(High early strength concrete shall only be used when specified or authorized by PTI

representative.)

Concrete for tremie slabs or site concrete if required, shall have a minimum strength of 14 Mpa at 28 days and contain a maximum of 0.82 of W/C ratio per cubic meter of concrete.

5.1 Testing

5.1.1 General

Testing of concrete supplied to this standard shall be subject to Project assessment requirements in accordance with AS 1379 unless specified otherwise. Laboratory tests of trial batches shall give average compressive strength at least 15% greater than the value in table 5.1. The water cement ratios given are the maximum value and shall not be exceeded even though the construction specimens exceed the specified strengths and even though laboratory mixed specimens are more than 15% higher than specified strengths. The surface water in the aggregate and water or other liquid in the admixture shall be included as part of the mixing water in computing the water content. The source and designation of all materials to be used concrete construction shall be approved by THE ENGINEER. Types and proportions of materials used in concrete mixes are to be made known when requested if tests are not made. All shipments of material or ready mixed concrete shall meet the applicable specifications and a certificate to that effect must accompany shipments.

5.1.2 Slump Slump testing is mandatory for concrete in which test cylinders are taken. Slump testing of concrete shall be in accordance with AS 1012.3. Any batch of concrete at delivery that falls outside the specified limits for slump, as shown in Table 5.1 and/or Table 5.2 will be liable for rejection. To avoid possible rejection the contractor is advised to target the lower end of the slump range. Any concrete in which the slump is less than the lower limit shown in the table 5.1 and/or table 5.2 may be rescued by

Standard Grades

Max w/c Ratio

Slump and tolerance

(mm)

Compressive Strength at 28 days Fc (Mpa)

21 0.68 100 20 21 28 0.57 100 20 28 35 0.48 80 15 35 40 0.41 70 10 41


10

using superplasticiser. The upper slump limit for superplasticed concrete shall be 130mm. Concrete in which the slump is 25mm and lower shall be rejected. Superplasticiser admixture shall refer to ASTM C1017, Type 1

Table 5.2 Recommended slumps for various type of construction using additives

5.1.3 Acceptance criteria

The strength of concrete shall be deemed to comply with this standard if it is in accordance with AS 1379 Specification and supply of concrete. In addition each sample tested shall have a minimum compressive strength as shown on table 5.1

6.0 ACCEPTABILITY OF CONCRETE 6.1 MATERIALS

6.1.1 Concrete mix Mixing water for concrete shall be fresh, clean and freed from injurious amounts

of oil, acid, alkali organic matter or other deleterious substances Fine aggregate shall be clean and well graded. Selection of suitable material shall be approved by THE ENGINEER. Coarse aggregate shall consist of hard uncoated particles of gravel or of crushed stone conforming to the latest version of ASTM C33. Crushed material shall be free from flat pieces, dust, soft particles and foreign matter. PTI representative shall have the right to take any samples of the materials including cement and aggregates etc, and test them in accordance with the


11

relevant Australian standard and/or ASTM standard at anytime during supply of concrete. Cylinder test shall be taken from batch truck in batch plant with minimum 2 samples required in every batch for 7, 14, 21, and 28 days testing unless notified/agreed otherwise by THE ENGINEER. The samples should not be taken from the very first or last portion of the batch discharge. The sample should be protected from sunlight, wind, and other sources of rapid evaporation during sampling and testing. For cylinder test contractor shall refer to AS 1012.1 clause 7 Sampling procedure In any case some test samples values indicate failure; Contractor shall establish the permitted standard deviation as shown in table 6.1. If the data shown that the standard deviation is outside the requirements then PTI representative have the rights to reject the concrete and If PTI representative deems that the structure is inadequate the cost of any demolition and replacement, or any remedial work shall be borne by the responsible contractor.

Specified compressive strength, fC , MPa

Required average compressive strength,

Fc, MPa

Less than 21 Fc + 7.0 21 to 35 Fc + 8.5 Over 35 1.10 Fc + 5.0

Adapted from ACI

Table 6.1 (Metric) Required Average Compressive Strength to establish Standard Deviation

6.1.2 Aggregates

Maximum size of coarse aggregate shall be as follows: Walls 200mm (8) and less in thickness.......................................................20mm Walls over 200mm (8) in thickness ............................................................25mm Ground floor slab ...........................................................................................25mm Supported ........................................................................................................20mm Piers and pedestals ........................................................................................25mm Pile caps and footings ...................................................................................40mm

6.1.3 Admixtures Admixtures shall not be used without the authorization of THE ENGINEER. Where used they shall conform to the following: Water reducing agent (cement dispersing), WRDA equal and conforming to the


12

latest ASTM Specification C 1017, Type 1. Initial set retarding agent equal and conforming to the latest ASTM Specification C 494

6.1.4 Steel Reinforcement

Reinforcing steel shall conform to A615M Grade 60, standard specification for deformed billet steel bars for concrete reinforcement. Cold drawn wire or welded wire fabric for concrete reinforcement shall conform to the requirements of the latest Specification ASTM A185 for Welded Steel Wire Fabric. Reinforcing steel shall be detailed and fabricated in accordance with CRSI (Concrete Reinforcing Steel Institute) Manual of Standard practice.

6.1.5 Storage of Materials

Cement shall be stored in weather tight buildings or storage containers which will provide protection from dampness and contamination. Caked or partly set cement shall be rejected. Fine and coarse aggregates shall be stored separately. Aggregate shall be placed and used so inclusion of dirt or other deleterious material is avoided. Reinforcing steel shall be placed on cribbing to prevent contact with the soil and shall be stored in an area not subject to heavy traffic or temporary flooding which might damage or coat the bar surface with mud or muck.

6.1.6 Mixing and Delivery

All mixing water shall be added to the concrete mix only at the plant. The concrete aggregates are to be measured by weight in the proportions determined from the approved design of mix. Accurate weighing equipment shall be provided for the proper weighing of materials to ensure accurate measuring equipment shall be regularly calibrated. The temperature of individual materials shall not exceed 49oC (140oF). When placed in the mixer and the resultant mixture shall never exceed 32oC (90oF). Mixing at site or central mixing plant shall be machine-mixed in a batch mixer. The mixer shall be capable of combining the aggregates, cement, and water into a uniform mass within the minimum time of discharging the mixture without segregation. For batch plant mixers; the mixer shall be charged so that water will enter the mixer over the full period of charging, beginning just before and ending just after the dry materials are added. The mixer shall rotate at the rotation speed recommended by the manufacturer. Concrete shall be mixed only in quantities required for current use; any concrete which has set so that it cannot be placed


13

properly shall not be used. The mixer shall be equipped with a suitable charging hopper, water storage space, and a water-measuring device. The water shall be started only while the mixer is being charged. After all materials are in the mixer, the batch shall be mixed the required time. After mixing, the entire content of the drum shall be discharged. The mixer shall be cleaned at suitable intervals. Plant mixed concrete will not be accepted if it is transported to the worksite in non-agitating equipment. The transporting units and any associated equipment shall be kept clean and in good mechanical repair. For dry mix concrete design is allowed for some cases with conditions as per approval from PTI representative and will be consider as a variation of approved mix (see clause 6.2.2). Dry mix design requirements and condition as follows: Delivery time from PTI batching plant to construction site is more than 3

hours All aggregates, cements and water is separated prior to mixing stages

Contractor shall calculate the water content required for dry mix concrete

admixtures as per drawing requirements and shall be approved / acknowledge by PTI engineer prior to batching the concrete

Dry mix concrete shall be batched using a rotating mobile mixer

equipment (agitating type) with minimum batching production capacity of 1/8 cu.meter

Contractor is responsible for the slump test and this shall be taken each

time batching is completed. For slump result refer to Table 5.1

Contractor shall be responsible for the concrete compressive strength test result as per drawing requirements

Cylinder test shall be taken for each 2 cu.meter of concrete batch.

Rejection of the concrete result as per clause 9.0 will also be applied in this dry mix design.

Centrally-Mixed concrete shall be transported to the site in a haulage unit equipped with a suitable-type agitator operating at a speed of not less than 2 rpm or more than 6 rpm. The volume of concrete in each load shall not exceed the manufacturer's normal rated capacity of the equipment. Concrete shall be conveyed from the mixer to point of placement as rapidly as possible. See clause 7.4 for placing concrete. The re-tempering concrete which has partially hardened, that is the re-mixing of concrete with or without additional cement, aggregate, or water will not be


14

allowed, and any concrete subjected to this treatment will be rejected. The contractor shall keep a record of each batch of concrete supplied, providing a relevant information of the wet concrete such as total water addition, slump, water cement ratio (w/c) etc, and also indicating adjustments in the batch weights as a consequence of corrections made due to variations in the moisture condition and absorptive characteristics of the aggregates. All aggregate and concrete testing by PTI representative (see also clause 5.1 and 6.1) will be carried out at PTI batching plant facility.

6.2 MIX ACCEPTANCE

6.2.1 Approved mix

A concrete mix approved by both PTI (project team) and Contractor shall become the Approved mix for the period of construction. It shall not be altered without any written approval of the PTI representative.

6.2.2 Variation of Approved Mix

If the contractor requires to vary the approved mix they are required to notify the PTI representative in writing of the reason for the proposed variation, the proposed mix details together with compressive strength and slump test results conducted on trial mixes showing that the concrete mix proposed is in accordance with project requirements. The contractor shall not vary the concrete mix until he/she receives the approval of PTI representative in writing.

6.3 ADMIXTURES

6.3.1 Water reducing

The contractor may use a water-reducing admixture in the concrete. The water-reducing admixture shall be in accordance with AS 1478 and/or ASTM C 494 and shall be approved by PTI representative. Suitable water-reducing admixtures shall be an essential ingredient of the approved mix design. Contractor shall submit details of the manufacture and type they intend to use for approval.

6.3.2 Superplasticiser

PTI representative may permit the use of approved high range water-reducing admixtures (superplasticisers) in special circumstances (see clause 5.1.2) but they shall not constitute an essential ingredient of the approved mix design. Additions shall only be made at the site. Dosage rates shall be predetermined, recorded, and controlled by contractor to avoid any overshooting the slump and to eliminate possible segregation


15

6.3.3 Accelerator admixtures

The contractor may use a concrete accelerator admixture into the concrete. This admixture agent shall refer to ASTM C494. The acceptance test of accelerator agents in to the concrete shall consider shrinkage control; corrosion control to the steel reinforcement; potential scaling. Contractor shall treat the steel reinforcement as per clause 7.2. This concrete mix modification shall be treated as variation of approved mix (see clause 6.2.2).

6.3.4 Retarder In some condition contractor may use the concrete retarder agent as per PTI representative approval and shall be recorded as variation of approved mix (see clause 6.2.2). Contractor shall control the shrinkage in concrete that may happen during curing time. Therefore acceptance test of retarders should be made with actual materials under anticipated job conditions.

6.3.5 Other Admixtures No other admixtures shall be used unless approved or requested in writing by PTI representative. This also shall be recorded as variation of approved mix (see clause 6.2.2) Addition sequences and dosage rates of all admixtures shall be as per manufacturers instructions.

7.0 INSTALLATION OF CONCRETE AND RELATED WORK

7.1 FORMWORK

7.1.1 Materials

The same kind of forms shall be used for all similarly exposed surfaces to produce a uniform appearance

7.1.2 Construction

1 Forms shall be mortar-tight and sufficiently rigid to prevent displacement or sagging between supports. Form surface shall be smooth and free from irregularities, dents, sags, or holes. Joints in formwork shall be in alignment both horizontally and vertically when used for permanently exposed faces.

2 Bolts and rods used for internal ties shall be arranged so that when forms are

removed, all metal shall be at least 40 mm from any concrete surface. Wire ties will not be permitted where the concrete surface will be exposed to weathering, and discoloration will be objectionable. All forms shall be constructed so that they can be removed without hammering or prying against the concrete.

3 Openings shall be provided at the base of the column, pier and at sufficient


16

intervals at the base of wall forms to allow for cleaning and inspection. 4 All formwork and centering shall be thoroughly cleaned before re-using. All

possible care shall be taken in the formwork to produce surfaces free from honeycomb and other defects.

5 All inserts, nailing strips, anchor slots, grounds etc., shall be built into the

concrete. 6 Edges of exposed surfaces shall have a 20mm chamfer unless otherwise shown or

noted.

7 Anchor bolt material shall be approved by PTI representative prior to installation; this also covers the site preparation, dimension and sizes etc. This term also applies to the installation of a new anchor bolt to an existing concrete plinth or any place mentioned in the drawings.

7.1.3 Coating

Before placing steel reinforcement or concrete, forms for exposed surfaces shall be coated with non staining mineral oil. Forms for unexposed surfaces may be thoroughly wetted in lieu of oiling immediately before placing the concrete.

7.1.4 Removing and Bracing and Shoring

Shoring and bracing shall remain in place until concrete has achieved sufficient strength to safely permit removal.

7.2 Steel Reinforcing

1 All chairs, ties, bootees, and spacers required to properly install reinforcing steel shall be provided as necessary. All accessories shall be furnished and installed in accordance with Manual of Standard Practice for Detailing Reinforced Concrete Structures as published by the Concrete Reinforcing Steel Institute.

2 Before being positioned, metal reinforcement shall be free from loose mill and

rust scale and from coatings such as mud or muck that would destroy or reduce the effectiveness of the bond. Where there is delay in depositing concrete, reinforcement shall be re-inspected and cleaned when necessary.

3 Metal reinforcement shall be accurately positioned and secured against

displacement by using annealed iron wire ties not less than 1.6mm (16 gauge) or suitable clips at not less than every third intersection. Reinforcement shall be supported by concrete or plastic supports, spacer, or hangers. Where indicated on the drawings or required by this specification, clips or supports shall not be placed in contact with the forms. No wood blocks or red brick spacers or chairs shall be used.

4 The minimum clear distance between parallel bars, except in columns, shall be

equal to the nominal diameter of the bars. In no case shall the clear distance


17

between bars be less than 25mm (1), nor less than and 1.5 times the maximum size of coarse aggregate. Where reinforcement in beams or girders is placed in two or more layers, the clear distance between layers shall not be less than 25mm (1), and bars in the upper layers shall be placed directly above those in the bottom layer.

5 At those surfaces of footings and other principal structural members in which the

concrete is deposited directly against the ground, metal reinforcement shall have a minimum covering as per AS 3600- Section 4.0 Design for durability

6 Reinforcing bars shall be placed in accordance with the drawings. Spliced bars

shall be placed in contact and wired. Splices shall be staggered. Where it is necessary to splice reinforcement at points other than shown on the drawings, the detail of the splice shall be approved by THE ENGINEER.

7 Exposed reinforcement intended for bonding with future extensions shall be

coated with a bitumastic type material or greased and wrapped with burlap and tied.

8 For some cases steel reinforcement shall be treated using paint protection prior to

concrete pouring to avoid any corrosion due to industrial climate, marine climate, and the using of calcium chloride in accelerator admixtures of concrete (see AS 3600-Section 4.9). For coating thickness protection shall be advice by paint manufacture. PTI representative shall be informed for approval or acknowledge.

9 Minimum steel reinforcement requirements for installation shall refer to AS 3600

section 13, PTI representative shall have the rights to reject the steel reinforcement inspection report if he/she deems that the installation is not comply with the standard.

7.3 Preparation.

1 A competent and experienced foreman shall be in charge of pouring operations at all times, and pouring of concrete shall not be started in any locations until the foreman has ascertained that the framework, reinforcing steel screens, and the placing of sleeves and inserts meet the requirements of the plans and specifications. The foreman shall also make certain that all other work required to be built into the concrete has been placed, including electrical and mechanical work.

2 The space in which concrete is to be placed shall be free of all debris and

pounding or flowing water. The surfaces against which the concrete is to be placed shall be clean and moist

3 The concrete surfaces to which a bond is to be secured shall be rough and free

from loose material or other matter interfering with a satisfactory bond. The surfaces shall be wet, scrubbed with steel brushes or brooms, kept damp and thoroughly brushed with a thin layer of mortar immediately prior to the placement of concrete. The mortar shall have the same cement-sand ratio as the


18

concrete. 4 A minimum thickness of blinding concrete is 50mm. Contractor can also use

plastic sheets to replace the blinding concrete. Material selection for plastic sheets shall be approved by PTI representative prior to installation and shall be recorded for quality control document.

5 Water shall be removed from the space to be occupied by the concrete before

concrete is placed. Any flow of water into excavation shall be diverted through proper side drains to a sump or shall be removed by other approved methods which will avoid washing the freshly deposited concrete.

7.4 Placing of concrete.

1 Concrete shall be placed before initial set has occurred and never after cement has been mixed with either water or aggregates for more than 60 minutes, except in cases where an approved retarder has been included in the design mix

2 All concrete shall be deposited in approximately horizontal layers not more than

600mm (24) thick. The concreting shall be carried on as a continuous operation as far as practicable until the placing of the course, section, panel, or monolith is complete. No concrete shall be deposited on other concrete that has hardened sufficiently to cause the formation of seams and planes of weakness within the section. If a section cannot be placed continuously, construction joints shall be located and made as approved by THE ENGINEER. The concrete placement shall be planned and managed to match the critical capacity of production/supply and/or placement.

3 Concrete shall be placed with the aid of approved mechanical vibrating

equipment. Vibration shall be transmitted directly to the concrete unless otherwise directed. The frequency of vibration shall be not less than 5000 cycles per minute. The intensity of vibration shall be sufficient to cause consolidation of the concrete in place. The vibration shall be of sufficient duration to accomplish through compaction. External vibration may be used for thin sections when internal vibration would be impracticable. Vibration shall be supplemented by forking or spading by hand adjacent to the forms on exposed faces in order to secure smooth, dense, even surfaces. The concrete shall be compacted and worked in an approved manner into all corners and angles of the forms and around reinforcement and embedded fixtures. Care should be taken not to over-vibrate causing segregation of the concrete

4 When dropping concrete through reinforcement, care shall be taken that no

segregation of the coarse aggregate occurs. There shall be no free vertical drop greater than 1.5 meters (5) unless elephant trunks are used. When the congestion of steel near the forms makes placing difficult, a mortar of the same cement-sand ratio used in the concrete shall be deposited first to cover the forms. In the case of walls, columns, or units of considerable height, concrete shall not be dropped from the top, but provisions shall be made for placing concrete through openings left in the forms for this purpose. Chutes shall not be used for placing concrete except for short distances, and only with the approval of THE


19

ENGINEER. When permitted, chutes shall be made of metal, or metal lined, of such design as to permit the continuous flow of concrete without segregation and shall be placed on a slope not flatter than one (1) vertical to two (2) horizontal.

5 Accumulation of water on the surface of the concrete due to water gain,

segregation, or other causes during placement and compacting shall be prevented as far as possible by adjustments in the mixture.

6 Exposed top surfaces of foundations, piers, footings, walls, and similar structures

shall be accurately leveled off and given a wood float finish except where grout is to be added, provide a rough surface, or where plans or specifications provide otherwise.

7 Suitable bulkheads with key ways shall be provided in the vertical construction

joints and elsewhere as directed or specified. 8 Concrete for tremie slabs shall be placed with a tremie bucket or pipe so as limit

the mixing of the concrete with the water in the sump area. Care shall be taken to ensure a reasonably level surface of the entire slab after completion of pouring.

9 The tremie pipe shall be water tight and large enough to allow a free flow of

concrete. It shall be kept filled with concrete at all times while depositing. The concrete shall be discharged and spread by moving the tremie so as to maintain as uniform a flow as practicable. If the charge is lost while depositing, the tremie shall be withdrawn and refilled.

7.5 Curing

Fresh concrete shall be protected from heavy rains, flowing water, and mechanical injury. All concrete shall be kept wet for a period of not less than seven days by covering with water, with an approved water saturated covering or by a system of perforated pipes of mechanical sprinklers or any other approved method, which will keep all surfaces continuously ( not periodically ) wet. Wood forms left in place for curing shall be kept wet at all times to prevent opening at the joints and drying out of concrete. Water for curing shall be generally clean and entirely free from any element which might cause staining or discoloration of the concrete.

7.6 Membrane Curing

1 Concrete roads, sidewalks, pavements and finished concrete floors may be cured by the application of a liquid membrane curing compound in lieu of curing described above if authorized by THE ENGINEER.

2 After finishing operations have been completed and immediately after the free

water has left the surface, the slab shall be completely coated and sealed with a uniform layer of membrane curing compound conforming to the Specification of Liquid Membrane-Forming Compounds for curing concrete (ASTM C 309) Type 1 or Type 4. Type 1 compound shall not be used on surfaces which are to receive waterproofing, resilient floor covering, painted or finished with metallic hardeners or color. Type 4 compound may be used on surfaces which are to receive


20

waterproofing. The compound shall be applied in a continuous, uniform film by an approved method in complete accordance with manufacturer's specification.

3 If rain falls on the newly coated pavement before the film has dried sufficiently to

resist damage or if the film is damaged in any other way, a new coat of material shall be applied to the affected areas equal in curing value to that specified for the original coat.

4 The treated surface shall be protected from injury for a period of at least seven

days. Foot or other traffic necessary to continued work will be permitted on the dried film provided any damage to the film is immediately repaired by the application of another coat of the compound.

5 Sufficient preliminary curing, with wetted burlap or cotton coverings, shall be

supplied as specified in clause 7.5, for pavement to be membrane cured in case of delays in the curing operation.

7.7 Weather Protection

1 Hot Weather: When necessary, arrangements for installation of windbreaks, shading, fog spraying, sprinkling, pounding, or wet covering of a light color shall be made in advance of placement, and such protective measures shall be taken as quickly as placing and finishing operations will allow.

7.8 Finishing Concrete Surfaces

1 All concrete work exposed to view, on the outside as well as inside, shall be pointed smooth. Forms shall be removed as soon as possible after pouring; all projections shall be cut away and all depressions, air holes and other roughness pointed up with a mixture of one-half cement and one-half silica sand (50:50 mix) while the concrete is still fresh. Surfaces shall be thoroughly wetted before pointing. All rough spots or surfaces shall be rubbed smooth with carborundum stone and water and left uniform in color and free from cement drippings. Only rubbing necessary to produce smooth surfaces free from form marks, cement drippings or their defects shall be done. For more detail in surface finishing please refer to clause 8.0

2 Fill in all holes and openings left in the concrete for steel, piping, sleeves, and

other Work. Such parts shall be filled with concrete unless otherwise detailed. After the work of other trades is in place. All filling shall be neat, and flush with adjacent surfaces.

3 Floor slabs where a hardened, lightened, dustproof surface is indicated on

drawings shall be treated as indicated on the drawings. Proprietary products shall be applied in strict accordance with the manufacturers specifications.

4 Concrete surface finish shall refer to PTI design requirements; maximum

tolerance for design concrete surface finishing shall refer to AS 3600 and/or 3610. PTI representative shall have the rights to reject the work if he/she deems that


21

the result is not meet with the design requirements; the recommended tolerance for concrete finishes shall refer to AS 3600 as shown in table 7.1. Contractor shall submits the reports to PTI representative for approval or acknowledge.

TOLERANCE ON: MEMBER Position/Size Surface Quality

Footings

Concealed Maximum deviation from any specified height, plan or cross-sectional dimension to be the greater of 1/200 times specified dimension or 5 mm (1).

Maximum deviation of any point on the surface from a straight line joining any two points on the surface to be the greater of 1/250 times length of the line or 10 mm(1).

Exposed As for concealed above plus Maximum deviation from plumb to be the greater of 1/200 times specified dimension or 5 mm(1, 2); Absolute position to be within 15 mm horizontally.

Class 4(3), or higher.

Slabs Maximum deviation from any specified height, plan or cross-sectional dimension to be the greater of 1/200 times specified Dimension or 5 mm (1). Surface level To be within 10 mm of specified level.

Exposed edges to be Class 3(3) or 2 (Maximum). Flatness Maximum deviation from a 3-m straightedge placed anywhere on the surface: 12 mm (4).

Columns and Walls Position 15 mm of specified position. Plumb 10 mm of plumb.

Concealed elements Class 4(3). Elements with applied finishes Class (3) to be specified to provide appropriate substrate. Elements viewed as a whole Class 3(3). Elements viewed in detail Class 2(3).

Architectural elements As appropriate for type of member.

Class 1, 2 or 3(3, 4).


22

External Pavements (driveways, footpaths, patios and other pedestrian pavements)

Surface level Non-graded pavement:

10 mm of specified level.

Graded pavement: 10 mm of a straight line between control points.

Control points at top and bottom of graded pavement: 10 mm of specified level.

Thickness Maximum deviation to be the greater of 1/200 times specified thickness or 5 mm (1).

Flatness Maximum deviation from a 3-m straightedge placed anywhere on the pavement: 12 mm.

Flatness and levelness

Finishing method/Pavement type

3-m straightedge tolerance Maximum deviations (mm)

Industrial pavements Surface level To be within 10 mm of specified level. Thickness Maximum deviation to be the greater of 1/200 times specified thickness or 5 mm (1).

Bull floated Straight edged (6) Flat Very Flat

12 8 6 3

Notes 1 In accordance with AS 3600. 2 If a Class 2 or 3 finish in accordance with AS 3610 is specified, the associated plumb tolerances apply. 3 In accordance with AS 3610. 4 a tighter tolerance may be required for some floor finishes, e.g. tiled, vinyl, polished. 5 As measured by the F-Meter method described on p2; see Table 1 for straightedge-tolerance equivalents. 6 Refers to a finishing process in which a long straightedge (3 to 4 m) is drawn across the surface transverse

to the direction of screeding to remove undulations in the transverse direction.

Table 7.1 Recommended Tolerances

7.9 Joints

7.9.1 Construction Joints

a. Construction joints shall be provided where shown on the drawings or as directed by THE ENGINEER.

b. The procedure for bonding new concrete to existing concrete shall be as specified

in clause 7.3.3. All construction joints shall be keyed.


23

c. Reinforcement shall be continuous through the joint. d. Water stops shall be as shown on contract drawings. The surface shall be clean

and free from oily substances. Concrete placed around the water-stops shall be vibrated carefully to insure that the concrete completely surrounds the water stops without the formation of air pockets or honeycomb.

Picture 7.1 Construction joints type

7.9.2 Expansion Joints

a. Expansion joints shall be provide in locations shown on contract drawings and constructed of asphalt-impregnated fiberboard conforming to ASTM D1751 and sealed with a poured joint sealer, or as otherwise detailed.

b. In no case shall reinforcement be continues through the joint.


24

c. Water stops shall be installed at expansion joints where required in accordance with clause 7.9.1d

d. Pre molded non-extruding fiber expansion joint material conforming to ASTM

D1751 shall be placed at locations indicated on the drawings. Material shall extend full depth of slab unless noted otherwise.

Picture 7.2 Expansion joint

7.9. 3 Control Joints

a. Control joints shall be provided in accordance with good engineering practice and in locations shown on contract drawings and formed by using a tool or saw cut and sealed with a poured joint sealer.

b. Reinforcing shall be continuous through the joint

Picture 7.3 Control joints

Addjointsealercompound


25

7.9.4 Joint sealer GAS pressure grade joint sealer manufactured by Sika Chemical Co. or an approved equal shall be applied at joints as required and in accordance with the manufacturer's recommendations. Concrete surfaces of joints shall be clean and free from moisture. Surfaces of concrete are to be primed as recommended by manufacturer of joint sealer.

7.10 Grouting

1 Grout under base plates for mechanical equipment supports and bedding plates to receive heavy equipment shall be a no-shrink metallic grouting proprietary product from a recognized supplier. Use of grout shall be approved by the ENGINEER in advance of application and shall be placed in accordance with manufacturer's recommendations. Minimum requirements for grouts material shall refer to ASTM C 1107

2 Grout under column base plates shall be one part Portland cement and two parts

sand using a maximum of water / cement ratio of 0.53:1.

8.0 SLAB FINISHES

8.1 Unformed Finish

For the Unformed surface the contractor is not required to provide formwork to provide either shape of finish to the surface however this work shall have the approval from the PTI engineer prior to the work. This category of concrete surface finish extends to all floors, pavings, slabs and inverts. These surfaces remain exposed when concrete casting is completed. The surface results from screed, float or trowel action, and texture sometimes provided by additional measures such as brooming, raking, grinding or scabbling. There are eleven standard finishes specified in the code. They relate primarily to the texture required for the surface to perform its intended function. The derivation of a particular class of finish frequently requires the surface to proceed through lesser classes (i.e. a U5 broomed finish is usually screeded to Class U1 and floated to Class U2 prior to the final texture being applied. The classifications for unformed finishes are shown in Table 8.1


26

Class Finish Technique Examples

U1 Screeded Hand sawing motion with straight-edge or mechanical vibrating screed

Finishes covered by backfill or concrete, footpaths, yards and driveways. First stage for placement.

U2 Floated Wood or bull float, or both. Generally manual but power driven equipment may be used

As for U1 where a higher standard of finish is required. Floors to receive carpets with underlay or similar coverings, inverts of siphons, flumes, floors of canal structures, spillways outlet works and stilling basins. Surfaces which are intended for use by ambulant disabled or wheelchair-bound persons.

U3 Trowelled Manual or mechanical steel trowelling of floated finish after concrete is sufficiently hardened to prevent excess fine material and water being worked to the surface, may be done in one or two stages depending on degree of smoothness required

Direct wearing floors such as in factories, warehouses and processing plants, Floors to receive thin sheet coverings, carpet and similar coverings. Inverts of water, tunnels and tunnel spillways. Not generally used for pedestrian or vehicular traffic where a smooth finish should be dangerous in icy or wet conditions. Is not suitable even when dry, for surfaces which are intended for use by ambulant disabled or wheelchair-bound persons.

U4 Machine Vibrating or oscillating screed or vibrating plate, or both, which may be supplemented by long handled metal, wooden, or rubber floats.

Used for durability where resistance to erosion and cavitations under action of high velocity water is especially required; and as firsts and second stage finishing for roads and airfield pavements prior to texturing with U5, U6 and U8 finishes.

U5 Shallow Textured

Hard or soft bristled brooms. Footpaths, yards, driveways, roads, pavements for aircraft.

U6 Deep textured

Wire broom or rubber tyning. Surface to receive a subsequent textured bonded concrete topping. Roads and runways where greater frictional resistances are required than can be obtained by U5 finish.

U7 Grooved Saw cutting or flailing by mechanical means. Treatment to existing roads and runways to provide frictional resistance and drainage paths for run-off to minimize aquaplaning.

U8 Grooved Mechanical grooving the fresh concrete surface after compaction and surface screeding techniques.

Roads and runways.

U9 Scrabbled Mechanical hammering of hardened concrete. Can be used on any pavement surface to produce a textured effect or to reduce high surfaces to the correct level or to rectify out-of-tolerance pavements.

U10 Special textured

The use of equipment to give special effects. Architectural effects on pavements and slabs, produced by rollers with drums of expanded mental, or profiled tempers on screed boards, and the like.

U11 Ground Finish

Low speed coarse stone grinding to remove thin weak surface layers/minor ridges and to produce and even 'glass paper' textured surface, that is, not a polished surface. Used as a second stage finish to U2, approximately 36-48 hours after laying.

Direct wearing floors such as in warehouses.

Table 8.1 Classes of floor, exterior pavement, and invert finishes


28

8.2 Formed Finish A formed surface shall be provided as per PTI engineering design requirements; contractor shall provide the shape and texture/finish to the concrete. The acceptability quality of the formed surface shall refer to AS 3610 (see table 7.2). PTI representative shall be informed for approval.

QUALITY OF SURFACE FINISH

Class 1 Class 2 Class 3 Class 4 Class 5

1. Blowholes Refer photographs in AS 3610 for examples

N/A N/A

2. Form face deflection Lesser of 2mm or span/360

Lesser of 2mm or span/270

Greater of 3mm or span/270

Greater of 3mm or span/270

N/A

Tolerance for straight elements with smooth surface, in millimeters % of readings

95 100

90 100

80 100 70 100 70 100

3. Face Step

Within the element 1 2 2 3 3 5 5 8 * *

At insitu construction joints 2 3 2 3 3 5 5 8 * * 4. Surface undulation**

l =300 [a-b] 1 2 2 4 3 4 5 7 * * L=1500 [a-b] 2 4 3 6 5 7 8 10

5. Flatness 1.25 m grid 4 5 6 7 7 10 * * * * At 5m over 10m (not applicable to precast concrete)

5 7 7 10 10 15 * * * *

6. Out of Plumb Height < 3m 3 5 4 6 5 7 * * * * 3 < height < 8 m (not applicable to precast concrete)

6 8 8 10 10 12 * * * *

Notes: * Limited by AS 3600 ** a and b are respectively the maximum and minimum distances from the straightedge

Table 8.2 Acceptable quality of formed surface (after AS 3610) 9.0 REJECTION

Concrete that is not accordance with this specification will be rejected by PTI representative. In particular, PTI representative will reject a load of concrete if:


29

1 Not mixed as per drawing design requirements 2 Significant variations to the current nominated mix are found by PTI representative,

or slump measured at delivery as specified in Clause 5.1.2 are out side the specified limits in Table 5.1 and/or 5.2

3 Maximum 60 minutes have elapsed since water was first added to the dry

ingredients 4 Delivered to worksite in non-agitating transport equipment or by a method not

accordance with AS 1379 5 The temperature of the concrete exceeds 320 C 6 Statements of compliance is not provided at time of delivery 7 The acceptability of concrete is not referring to section 6.0 and 7.0 for pre-pouring

and pouring stages. 8 Concrete finish is not referring to section 8.0 for slab finishes

If 28 days characteristic compressive strength test done by PTI representative indicate that hardened concrete (i.e.: that that has been laid) is not in accordance with the drawing specification required, PTI representative will examine all concrete structures affected in accordance with methods specified in AS 1379. If PTI representative deems that the structure is inadequate the cost of any demolition and replacement, or any remedial work shall be borne by the responsible contractor.

The statement of compliance (see clause 10.0) from contractor will not be accepted and will not be valid anymore if the test result indicating that contractor is failed to do the work as per drawing specification required.

10.0 STATEMENT OF COMPLIANCE The contractor shall provide to PTI representative at time of delivery a statement of compliance with each load of concrete delivered which shall state that the batch delivered is in compliance with the approved design mix Contractor shall also provide a report with each load of concrete delivered, on which the following information shall be recorded:

1. Date of delivery 2. Grade of concrete and delivery

3. Cement type and cement content (kg/m3)

4. Water cement ratio (free water after allowing absorption of aggregates)

5. Plant at which concrete mix was batched 6. Quantity of concrete in delivery vehicle

7. Time vehicle left batching plant


30

8. Time vehicle start unloading concrete at worksite

9. Time discharge of load was completed

10. Place concrete was delivered


31

Extra page for revision

csp003 - concrete rev.1.pdf

Documents