spec concrete_07100 concrete

VOLUME 3 – TECHNICAL SPECIFICATION

DIVISION 7CONCRETE WORKS

SECTION 07100 - CONCRETE AND CONCRETE STRUCTURES.......................2

SECTION 07200 - PRECAST CONCRETE PILES..............................33

SECTION 07250 - BORINGS FOR PILE BEARING CAPACITY............43

SECTION 07300 - CAST-IN-SITU PILE...........................................47

SECTION 07350 – PILE DYNAMIC TESTING...................................63

SECTION 07400 - PRESTRESSED CONCRETE................................67

SECTION 07500 - REINFORCING STEEL.......................................83

SECTION 07600 - BRIDGE BEARINGS..........................................91

SECTION 07700 - WATERPROOFING..........................................101

SECTION 07800 - EXPANSION JOINT.........................................105

Section 07900 - Bridge Drainage.............................................................112

Volume 3 – Technical Specification Concrete and Concrete Structures- 1 -

SECTION 07100 - CONCRETE AND CONCRETE STRUCTURES

TABLE OF CONTENTS

1. DESCRIPTION......................................................................4

2. REFERENCE STANDARDS.....................................................4

3. CONSTRUCTION REQUIREMENTS..........................................63.1 Materials for Concrete.....................................................................6

3.1.1 General.............................................................................................................63.1.2 Portland Cement...............................................................................................63.1.3 Water for Concrete Mixing and Curing...............................................................73.1.4 Aggregates........................................................................................................73.1.5 Admixtures........................................................................................................9

3.2 Concrete Classes.............................................................................93.2.1 Approved Mix Design......................................................................................103.2.2 Water - Cement Ratio......................................................................................103.2.3 Adjustments during Progress of Work..............................................................113.2.4 Contents of Chloride and Sulphate..................................................................113.2.5 Submittals.......................................................................................................11

3.3 Formwork and Falsework...............................................................123.3.1 Design.............................................................................................................123.3.2 Construction of Formwork...............................................................................143.3.3 Removal of falsework and formwork...............................................................16

3.4 Concreting....................................................................................173.4.1 General...........................................................................................................173.4.2 Batching..........................................................................................................173.4.3 Mixing and Delivery........................................................................................193.4.4 Concrete Consistency......................................................................................203.4.5 Pumping..........................................................................................................203.4.6 Placing and Compacting..................................................................................203.4.7 Placing of Concrete in or Under Water.............................................................223.4.8 Weather Precautions.......................................................................................223.4.9 Continuity of Concrete Work...........................................................................23

3.5 Joints............................................................................................233.5.1 General...........................................................................................................233.5.2 Construction Joints..........................................................................................233.5.3 Bonded Construction Joints.............................................................................243.5.4 Joint between the deck slab and the coping....................................................25

3.6 Concrete Finishing........................................................................253.6.1 Finishing Concrete Surfaces............................................................................253.6.2 Remedial Treatment of Finished Surfaces........................................................263.6.3 Fixing of Ironwork............................................................................................263.6.4 Reconstruction of Faulty Work.........................................................................26

3.7 Curing...........................................................................................263.7.1 Methods using water.......................................................................................263.7.2 Preventing Moisture Loss................................................................................273.7.3 Waterproof Paper............................................................................................273.7.4 Plastic Sheets..................................................................................................273.7.5 Curing Compounds..........................................................................................27

3.8 Precast Concrete...........................................................................283.8.1 Materials.........................................................................................................283.8.2 Fabrication......................................................................................................28

3.9 Quality Control of Concrete.............................................................293.9.1 General...........................................................................................................293.9.2 Technicians at Mixing Plant.............................................................................29


3.9.3 Sampling of Mixed Concrete............................................................................303.9.4 Compressive Strength Testing.........................................................................30

3.10 Testing frequencies.......................................................................313.11 Acceptances Test and Tolerances....................................................30

3.11.1 Strengths.....................................................................................................303.1.2 Dimensions..................................................................................................30

4. MEASUREMENT AND PAYMENT...........................................334.1 Method of Measurement................................................................334.2 Basis of Payment...........................................................................33


1. DESCRIPTION

This specification consists of the supply, transport and placing of concrete

mixes of different classes and concrete construction work in accordance with

the lines, grades, sections and other detail shown on the drawings or subject

to approval by the Engineer.

The figure below shows the applicable referencing of structural sections:

2. REFERENCE STANDARDS

The following Standards in their latest edition shall be particularly applied to

the works covered by this Specification.

TCVN 5438-04 Cements - Standard Specification for Terminology and definitions

TCVN 5439-04 Cements - Standard Specification for Classification

TCVN 2682 -

92Standard Specification for Portland Cement

TCVN 4029-85Cements - Technical requirement procedure for physical contents

testing

TCVN 4030-03 Cement. Test method for determination of fineness

TCVN 4031-85Cements - Method for determinatoin of standard workability

setting time and volume stability

TCVN 4032-85Cements - Methods for determination of bending and compressive

strength

TCVN 6016-95 Cements - Test methods - Determination of strength

TCVN 6017-95 Cements - Test methods - Determination of setting time and soundness

AASHTO M6 Fine Aggregate for Portland Cement Concrete; AASHTO M33 Preformed Expansion Joint Filler for Concrete (Bituminous Type)AASHTO M80 Coarse Aggregate for Portland Cement Concrete;

Volume 3 – Technical Specification Concrete and Concrete Structures

Expansion Joint;

Concrete Hand Rail;

RC Slab ;

Prestreed Beam& Concrete Form ;

Apron ;

Wing Wall ;

Footing orPile Cap ;

Pier ; Cross Head ;

Reinforcing Steel ;

Bearing ;

Figure for Payment Item (for Reference only)

Approach Slab:

Cross Beam;

Box Culvert ;

Steel Hand Rail;

Precast Concrete Pile Cast-in-Situ Pile ;

Water Roof:

- 4 -

AASHTO M85 Portland Cement; AASHTO M115 Asphalt for Damp-proofing and Waterproofing; AASHTO M116 Primer for Use With Asphalt in Damp-proofing and

Waterproofing; AASHTO M118 Coal-Tar Pitch for Roofing, Damp-proofing, and Waterproofing; AASHTO M148 Liquid Membrane-Forming Compounds for Curing Concrete; AASHTO M153 Preformed Sponge Rubber and Cork Expansion Joint Fillers for

Concrete Paving and Structural Construction; AASHTO M182 Burlap Cloth made from Jute or Kenaf; AASHTO T22 Compressive Strength of Cylindrical Concrete Specimens; AASHTO T23 Making and Curing Concrete Test Specimens in the Field; AASHTO T96 Resistance to Abrasion of Small Size Coarse Aggregate by Use

of the Los Angeles Machine; AASHTO T119 Slump of Portland Cement Concrete; AASHTO T121 Mass per Cubic Meter, Yield, and Air Content (Gravimetric) of

Concrete; AASHTO T134 Moisture-Density Relations of Soil-Cement Mixtures; AASHTO T141 Sampling Freshly Mixed Concrete; AASHTO T224 Correction for Coarse Particles in the Soil Compaction Test; ASTM C31 Making and Curing Concrete Test Specimens in the Field; ASTM C33 Concrete Aggregates; ASTM C39 Compressive Strength of Cylindrical Concrete Specimens; ASTM C40 Organic Impurities in Fine Aggregates for Concrete; ASTM C87 Effect of Organic Impurities in Fine Aggregate on Strength of

Mortar; ASTM C88 Soundness of Aggregate by Use of Sodium Sulfate or

Magnesium SulfateASTM C91 Masonry Cement; ASTM C94 Standard Specification for Ready-Mixed Concrete; ASTM C109 Compressive Strength of Hydraulic Cement Mortars (Using 2-in.

or 50-mm Cube Specimens); ASTM C123 Lightweight Pieces in Aggregate; ASTM C136 Sieve Analysis of Fine and Coarse Aggregates; ASTM C138 Unit Weight, Yield, and Air Content (Gravimetric) of Concrete; ASTM C143 Slump of Portland Cement Concrete; ASTM C144 Aggregate for Masonry Mortar; ASTM C150 Portland Cement; ASTM C227 Potential Alkali Reactivity of Cement-Aggregate Combinations

(Mortar-Bar Method); ASTM C287 Chemical-Resistant Sulfur Mortar; ASTM C294 Constituents of Natural Mineral Aggregates; ASTM C295 Petrographic Examination of Aggregate for Concrete; ASTM C494 Chemical Admixtures for Concrete; ASTM C827 Change in Height at Early Ages of Cylindrical Specimens of

Cementations Mixtures; ASTM C1017 Chemical Admixtures for Use in Producing Flowing Concrete; ASTM C1077 Laboratories Testing Concrete and Concrete Aggregates for Use

in Construction and Criteria for Laboratory Evaluation.


3. CONSTRUCTION REQUIREMENTS

3.1 Materials for Concrete

3.1.1 General

(a) The Contractor shall submit samples of all materials to be used in

concrete mixes together with test results confirming their compliance

with this specification for the approval of the Engineer.

(b) The Contractor shall use approved materials to prepare mix designs

and for trial mixes to be approved by the Engineer.

(c) No materials shall be delivered to the Site until materials, mix designs

and trial mixes have been approved by the Engineer.

3.1.2 Portland Cement

(a) Cement shall be Portland cement type I complying in all respects with

ASTM C150 (AASHTO M85). However the Contractor may submit to

the Engineer for his approval fully supported proposals for the use of

other types of cement. All cement shall be manufacturer’s standard

cement unless otherwise specified on the drawings. Only one brand of

cement shall be used for all concrete works throughout the Project

unless otherwise authorized by the Engineer.

(b) The Contractor proposed source of supply of cement shall be

submitted to the Engineer for his approval. All deliveries of cement to

site shall include appropriate test certificates, certified by an

independent agency in the country of origin, confirming that the

material delivered complies with the specification.

(c) Cement shall be delivered to the Site in sealed bags or in bulk.

(c) Bagged cement shall bear the manufacturer’s name, cement type and

the date of manufacture and shall be stored in waterproof sheds or

other such temporary buildings used exclusively for the storage of

cement. Cement shall be stored in dry conditions on areas raised

above ground level. Storage capacity shall be sufficient to hold enough

cement for the largest units to be cast. Bags shall not be stored more

than 8 high and a free passage of at least one meter shall be left

between the cement and the side walls of the sheds.

(d) Cement delivered by bulk carriers shall be stored in silos made for

cement storage. All handling shall be by methods that prevent

contamination of the cement. The silos shall be provided with interior

moisture control devices that keep the cement dry and prevent

premature hydration. The silos shall be provided with access ladders

and access points to enable samples to be taken from various levels of

each silo for testing purposes.

(e) Access ways shall be provided between storage containers such that

every container can be visually inspected. Each delivery shall be

stored separately from previous deliveries. Deliveries shall be used in


the order in which they were delivered. Any delivery which has become

caked or otherwise adversely affected shall be removed from the Site

at the Contractor’s expense.

(f) The Contractor shall provide weighing machines which shall be kept

permanently in each shed for checking the weight of the bags.

3.1.3 Water for Concrete Mixing and Curing

(a) The Contractor’s proposed water source shall be submitted to the

Engineer for his approval together with test results confirming that

water from the source complies with this specification.

(b) Water for concrete mixes, curing concrete and other products

containing cement shall be clean water free from oil, salt, acid, sugar,

vegetable or any other substance injurious to the concrete unless

otherwise authorized in by the Engineer.

3.1.4 Aggregates

(a) Aggregates shall be free of substances that react deleteriously with

alkali in the cement sufficiently to cause unacceptable expansion of

the concrete. The Engineer’s approval of aggregate sources will be

based on satisfactory evidence furnished by the Contractor that the

aggregate is free from such materials. This evidence shall include

certified records of tests by a testing laboratory that the aggregates

meet the requirements of ASTM-C227 and may include service records

of concrete of comparable properties placed under similar conditions

of exposure. Tests shall be made in accordance with ASTM-C287 and

ASTM-C295 ASTM C1077.

(b) All aggregates shall consist of tough, hard, durable uncoated particles.

The Contractor shall be responsible for processing aggregates to meet

the requirements of this specification. The Contractor’s proposed

sources of aggregates shall be submitted to the Engineer for his

approval. Samples shall be taken in the presence of a representative of

the Engineer and the Contractor for testing and approval before

materials are brought to the Site.

(c) Aggregates shall be stored in stockpiles that ensure the materials

remain free draining and are adequately separated to prevent cross

contamination. Stockpiles shall be placed on a properly prepared

surface to ensure no contamination occurs when materials are re-

handled. Materials shall be handled in a manner which avoids

segregation. All stockpiles are to be labelled with markers indicating

the material type in the stockpile. Materials previously approved but

rendered unacceptable due to inadequate storage or handling will be

rejected. Aggregates shall be stored in sufficient quantity to ensure

that there is no interruption of concreting work at any time.

Aggregates shall be stock near mixing plant, Before mixing aggregates shall be comply enough moisture, aggregates shall


be checked and approved by the engineer.

(d) Fine and coarse aggregates shall be tested in accordance with the

standards below. Source approval shall be withdrawn if aggregates do

not meet the requirements of this specification during routine testing.

ASTM C39 Compressive Strength

ASTM C40 Organic Impurities

ASTM C87 Mortar Strength

ASTM C88 Soundness

ASTM C123 Coal and Lignite

ASTM C136 Sieve Analysis

(1) Fine Aggregate

(a) Fine aggregate shall consist of natural sand with hard, strong,

durable particles or other inert materials with similar

characteristics. Fine aggregate shall be clean and free from

extraneous materials, clay balls, organic matter or other

detrimental material in accordance with AASHTO M6. The

maximum combined quantity of soluble chloride and sulphate in

fine aggregate shall not exceed 1,000 ppm.

(b) Fine aggregate shall be reasonably graded and shall meet the

grading requirements mentioned in Table 1.

(c) Fine aggregate shall be of such uniformity that the fineness

modulus as defined in AASHTO M6 shall not vary more than 0.20 in

either way from the fineness modulus of the representative

samples used in the mix designs.

Table 1 : Grading Requirements of Fine Aggregate

Sieve Size (mm)

Percent Passing by Weight （%）

9.5 1004.75 95 - 1002.36 80 - 1001.18 50 - 85

0.600 25 - 600.300 5 - 300.150 2 - 10

(2) Coarse Aggregate

(a) Coarse aggregate shall be crushed aggregate and shall be

homogeneous, clean, and free from extraneous materials, clay

lumps, organic matter, and other detrimental materials. Coarse

aggregate shall meet the requirements of AASHTO-M80 and ASTM

C33.

(b) Coarse aggregate shall be reasonably graded and shall meet the

grading requirements in Table-2-1 in subsection 3.2 Concrete

Classes.


(c) The percentage wear of the aggregate shall not be greater than

50 as determined by AASHTO-T96. Coarse aggregate shall

withstand at least five cycles of immersion and drying in both

sodium sulphate and magnesium sulphate solutions, as

prescribed in the soundness test, and shall show an average

weight loss of not more than 15 percent.

3.1.5 Admixtures

The use of any admixtures will require the approval of the Engineer. Each

type and each location or purpose shall be approved individually. Approval

will be dependent upon the submission of mix designs and satisfactory trial

mixes to demonstrate the function of the admixture.

3.2 Concrete Classes

(a) Concrete shall be of one of the classes shown in Table-2-1. All concrete

classes shall be tested using cylinders in accordance with AASHTO T22

and T23 (ASTM-C39 and C31 respectively).

(b) The strength requirements for each class of concrete as determined by

testing cylinders at 7 and 28 days in accordance with the requirements

of this specification are given in table 2.1 below. The table also includes

other information which is provided as guidance for the Contractor in

determining the contents and properties of his proposed concrete

mixes.

(c) The class of concrete to be used in each part of the Works shall be as

detailed on the drawings subject to confirmation by the Engineer.

However a guide is given in the 2.2 below.


Table 2.1 Concrete Classes

C50 C35 C30C30(for bored pile)

C25 C20 C10

Minimum Concrete Strength at 28days (150x300mm Cylinder) (Mpa)

50 35 30 30 25 20 10

Maximum Size of Course Aggregate (mm)

20 20 20 20 20 25 40

Minimum Cement Content (kg/m3)

450 380 350 350 330 280 175

Maximum W/C Ratio (%) 30 39.5 45 49.4 50 55 76

Slump (mm) 50-100

50-100

50-100

130-170 50-100

50-100

25-75

Coarse Aggregate

Sieve Size 37.5mm 100 100 100

25.0mm 100 100 100 100 90-100

90-100

95-100

19.0mm 90-100

90-100

90-100

90-100

12.5mm 30-70 30-70 30-70 30-70 25-60 25-60 25-60

Table 2.2 Concrete class - location

Concrete Class LocationClass C50 Precast Girder (Super T)Class C35 CIP Deck Slab (incl Link Slab), Crossbeam of Super TClass C30 Abutment, Pier, Precast Concrete Plank for Super TClass C30 (Bored piles) Bored PileClass C25 Parapet, Pedestal of Lamp Post, Approach SlabClass C20 Sealing ConcreteClass C10 Blinding Concrete

(d) Acceptable ranges for concrete slump shall be determined by

appropriate mix design and subsequent trial mix testing. Slumps shall

be measured in accordance with AASHTO T119.

3.2.1 Approved Mix Design

(a) The Contractor shall submit his proposed mix designs to the Engineer

for his approval and prepare samples in order to Engineer checked and approved samples before carying out mixing concrete on a large scale. The mix design shall include the target mean strength for

the mix and shall be submitted with the results of satisfactory tests

from trial mixes. The mix design and the trial mixes shall use only those

materials that have previously been given source approval by the

Engineer.

(b) No concrete work will be allowed to commence until the Engineer

approves the Contractor’s proposed mix design(s).

(c) A new mix design shall be submitted to the Engineer for his approval if

there are any changes in characteristics or source of supply of any of

the component parts of the mix. Any delay due to such changes shall

be entirely the responsibility of the Contractor.

(d) During the execution of the Works, the Engineer may require additional

tests to be made on the work mix to check compliance with the

approved Mix Design.

3.2.2 Water - Cement Ratio

(a) The Contractor’s proposed water content and water cement ratio shall

be included in the mix designs, supported by trail mixes, submitted to

the Engineer for his approval. The water content shall be the least

amount that shall produce a workable homogeneous plastic mixture.

Excess water shall not be permitted and any batch containing such

excess shall be rejected.

(b) The total water content for any batch of concrete shall include an

allowance for water contained in the aggregates. The Contractor shall


determine the water content of the aggregates before concrete

batching begins and admixture (if any). The water added to the mix

shall be adjusted for the water contained in the aggregates.

(c) Frequent slump tests shall be carried out to ensure that the workability

of the concrete remains consistent.

3.2.3 Adjustments during Progress of Work

After a mix design has been approved, the mix shall not be changed during

the progress of the work except as follows:

If it is found impossible to obtain concrete of the desired workability with the

mix proportions originally determined, changes in aggregate weights may be

made subject to the approval of the Engineer.

If it is found impossible to produce concrete of the minimum allowable

strength specified, the cement content may be increased subject to the

approval of the Engineer.

3.2.4 Contents of Chloride and Sulphate

(a) The amount of chloride in the concrete mass shall not exceed 1,000

ppm of the total concrete mass, or 6,000 ppm of the amount of cement

in the mix.

(b) The amount of sulphate in the concrete shall not exceed 800 ppm of

the total concrete mass, or 5,000 ppm of the amount of the cement in

the mix.

(c) The amounts of chloride and sulphate shall be determined by

recognized methods of laboratory analyses of the cement, aggregates,

water and admixtures.

3.2.5 Submittals

(a) The Contractor’s submissions shall be made well before the start of any

concrete work on site. The Contractor shall bear in mind the time

required for submitting and gaining the approval of all constituents of

the mix and the time required to prepare mix designs and prove them

by trial mixes and subsequent cylinder tests. The Contractor shall also

allow sufficient time for the Engineer to review the submissions and to

conduct any additional trial mixes and tests that might be necessary.

(b) Each mix design submittal shall include, but not be limited to, the

following:

(a) Project identification;

(b) Name and address of the Contractor and concrete producer;

(c) Mix design designation;

(d) Class of concrete and intended use;

(e) Material proportions;

(f) Name and location of material sources for aggregate, cement,


admixtures, and water;

(g) Type of cement and type of cement replacement if used. Fly ash, ground iron blast-furnace slag, or silica fume may partially replace cement if complying with pertinent specifications subject to approval by the Engineer.

(h) Cement content in kilogram per cubic meter of concrete;

(i) The saturated surface dry batch mass of the coarse and fine aggregates in kilogram per cubic meter of concrete;

(j) Water content (including free moisture in the aggregate plus water in the drum, exclusive of absorbed moisture in the aggregate) in kilogram per cubic meter of concrete;

(k) Target water/cement ratio;

(l) The water/cement ratio for modified concrete is the ratio of the mass of water to the combined mass of Portland cement and cement substitute;

(m)

Dosage of admixtures;

(n) Sieve analysis of fine and coarse aggregates;

(o) Absorption of fine and coarse aggregates;

(p) Bulk specific gravity (dry and saturated surface dry) of fine and coarse aggregates;

(q) Dry rodded unit mass of coarse aggregate in kilogram per cubic meter;

(r) Fineness modulus (FM) of fine aggregate;

(s) Material certifications for cement, admixtures, and aggregate (if applicable);

(t) Target values for concrete slump with and without high-range water reducers;

(u) Target values for concrete air content (if required);

(v) Concrete unit mass;

(w) Compressive strengths of 7 and 28-day concrete.

3.3 Formwork and Falsework

3.3.1 Design

(a) The Contractor shall submit calculations, shop drawings, working

drawings, and details of all materials and manufactured goods

included in the formwork and falsework to the Engineer for his

approval well before the start of construction work on site. Work shall

not start until approval has been given.

(b) The Contractor shall be solely responsible for the design of the

formwork and its supporting falsework. The design shall include all

necessary strutting, bracing and temporary foundations to ensure the

support of all temporary works items, equipment, the weight of the

plastic concrete or any other loading resulting from methods adopted

for the placing and compaction of the concrete or any incidental


loading. There shall be no harmful deformation of the forms during

the concreting operation. No accessory for supporting the formwork or

staging shall be built into the permanent structure except with the

Engineer’s approval.

(c) The design shall be appropriate for such temporary works and shall take into full consideration all temporary loading cases arising from the procedures and work sequences, the prevailing conditions at the site, in particular likely wind loading, and the nature of the existing ground. The Contractor shall carry out all additional soils investigation necessary to confirm his assumptions concerning the nature of the existing ground.

(d) Formwork and falsework shall be designed for vertical load and lateral

pressures in accordance with ACI 347 and, where appropriate, any

increased or re-adjusted loading that may result from pre-stressing

forces. If retarding admixtures are used, their effect shall be duly

considered during the calculation of the lateral pressures of the fresh

concrete. The formwork and falsework shall be designed and

constructed to ensure completed concrete surfaces comply with the

tolerances specified in ACI 347 or elsewhere in this specification.

(e) The shop drawings and working drawings shall show the proposed

details of construction of members, spacing of bents, posts, studs,

walings, stringers, collars, bolts, wedges, bracing, rate of pour, and

the manufacturer’s recommended safe working capacity of all form

ties and column clasps. All assumptions, dimensions, material

properties and other data used in the structural analysis shall be

noted on the shop drawings. The Contractor shall furnish copies of

the design calculations to the Engineer for his consideration when

approving the Contractor’s proposals.

(f) The calculations and drawings shall be certified and stamped by a qualified structural engineer experienced in the preparation of such designs.

(g) When manufactured formwork, shoring or scaffolding units are used,

the manufacturer’s recommendations for allowable loads shall be

followed. In such cases the Contractor shall provide certificates and

test reports or records of successful experience. Reduced allowable

load values may be required for materials which have or will

experience substantial reuse.

(h) Where falsework openings are required for maintaining traffic flows or

for pedestrian access the Contractor shall provide all necessary

additional features to protect the public and to ensure that the

falsework will remain stable, particularly if subject to impact by a

vehicle. Where openings are provide the design shall include but not

be limited to

(i) the anchoring of stringers to caps or frames in adjacent spans.

(ii) adequate bracing during construction or removal, and


(iii) at least a 300mm. gap between the falsework and protective

railing.

3.3.2 Construction of Formwork

(a) The formwork shall be constructed accurately to represent the shape

of the structure as detailed on the drawings. It shall be of suitable

design and appropriate construction and shall have been approved by

the Engineer. The Contractor shall make any necessary adjustments

to allow for shrinkage, settlement or deflection which may occur

during construction so that the finished concrete sections conform

accurately to the specified dimensions true to line, level, location and

camber.

(b) Wooden boards shall be cut accurately to shape and fixed such that

there are no openings after the wetting of the formwork prior to

placing concrete.

(c) Unless otherwise required by the Engineer concrete class C10 shall be

placed to a minimum depth of 10 cm in the footing of foundations to

structures to provide a working platform and to ensure stability of the

foundation soils. The concrete area shall be sufficient to provide

support for the Contractor’s proposed formwork.

(d) All formwork surfaces shall be fabricated to comply with the

requirements of clause 3.6 of this specification unless otherwise

required by the drawings or other Specification Sections. Surfaces

which are completely enclosed or hidden below the permanent

surfaces of the ground or surfaces with no specified finish may be

formed of sawn boards or similar material. Any lumber or material

which is damaged or warped prior to placing of the concrete shall be

rejected. All exposed surfaces shall be formed using plywood or

metal formwork. The surfaces of plywood or metal formwork shall be

kept clean and in good condition at all times to ensure that all

concrete surfaces have a consistent appearance that complies with

this specification. The Engineer will reject formwork that does not

comply with this specification and rejected formwork shall be removed

from site.

(f) All exposed sharp edges shall be chamfered using triangular fillets not

less than 2 cm by 2 cm in size, unless otherwise directed by the

Engineer. The triangular fillets or chamfer strips shall be milled from

clear, straight grain lumber and shall have a finished surfaced on all

sides. Curved surfaces shall be formed of plywood, metal, or other

suitable material.

(g) All formwork and falsework shall be constructed using stiff walings

(separators) fixed at right angles to studs. Walings shall be paired and

tied together by ties or clamps which pass through the formwork.

Bolts, ties and form clamps to hold formwork together shall be


positive in action and shall have sufficient strength and be sufficient

in number to prevent spreading of the forms. Lifting anchors may be

installed in pre-cast members. Bolts, ties, form clamps and lifting

anchors shall be entirely removed or cut back, leaving no metal within

3 cm from the concrete surface.

(i) Drainage holes and weep holes shall be constructed as detailed on

the drawings. Forms for weep holes shall be approved by the

Engineer.

(j) The Contractor shall ensure that all required inserts, anchors,

expansion joint and bearing elements, sleeves, and other items in this

specification are installed in the formwork. The Contractor shall

coordinate the installation with other trades to ensure proper location

of such items. Ends of piping and sleeves embedded in concrete shall

be closed with caps or plugs.

(k) No concrete shall be placed in the formwork until construction of the

formwork and falsework, the provision and fixing of reinforcement, the

provision of ducts, anchorages, and pre-stressing steel and the

provision and fixing of all inserts, anchors and expansion joint and

bearing elements has been completed for the unit and the unit has

been cleaned and sealed to prevent grout leaks all to the satisfaction

of the Engineer.

(l) With the exception of permanent formwork, all formwork surfaces

which shall have concrete against them shall be treated with a release

agent which shall be subject to the approval of the Engineer. Release

agents shall be applied strictly in accordance with the manufacturer’s

instructions and shall not come into contact with the reinforcement or

prestressing tendons and anchorages. Different release agents shall

not be used in formwork for concrete that will be visible in the finished

Works. Forms shall be saturated with water before concrete is placed.

The surfaces of formwork shall be free from any material that shall

adhere to or discolour the concrete and all materials applied to the

surfaces shall be non-staining.

(m) The general tolerances in Tables-3 below shall apply to dimensions

shown on the drawings.

Table 3 General Tolerances

Item Tolerances

Spacing of reinforcement Within ±10mm

Concrete cover for Superstructure

Within ±5 mm


Concrete cover for other structure

Within ±10mm

(n) If during the placing of concrete movement of the formwork or falsework occurs that exceeds allowances in the Contractor’s design or will result in completed work unacceptably out of tolerance, then placing of concrete shall stop. Placing of concrete shall not re-start until such time as corrective measures satisfactory to the Engineer have been taken by the Contractor. If such measures are not taken before the initial set of the concrete placing of concrete shall not be permitted to re-start. In such case a joint shall be formed and all unacceptable concrete removed all to the satisfaction of the Engineer.

3.3.3 Removal of falsework and formwork

(a) Concrete shall have reached the strengths indicated in Table 4 below

before the removal of formwork and false-work. No formwork or

falsework shall be removed without the approval of the Engineer.

Table 4 Removable Time of Form/False work

Formwork/Falsework Time / % of Design Strength of Concrete

Pre-tensioned T beams - / 85%

Support members/Pier head (30 MPa) - / 100%

Centring under girders, beams, frames or arches.

14 days / 80%

Floor slabs 14 days / 70%

Columns 2 days / 70%

Walls, sides of beams and all other vertical surfaces

1 day / 70%

To enable finishing, forms used for parapets, barriers, and exposed vertical surfaces shall be removed between 24 hours and 48 hours after casting, depending on

weather conditions.

(b) In continuous structures, falsework for a particular span shall not be

released until adjoining spans which will be subject to loading as a result of such release have reached their specified strengths. Falsework or formwork for all spans which affect the loading of a particular span shall be released before concrete is placed in railings, parapets or other elements for the particular span. Release of falsework and formwork for continuous spans or cantilevers shall be carried to ensure a gradual application of working stresses.

(c) Where appropriate formwork to columns shall be removed before the removal of formwork and falsework to beams and girders to ensure the columns are satisfactory.

(d) At the discretion of the Contractor and subject to the approval of the Engineer, formwork and falsework may be left in place for footings


within coffer dams or crib work should the removal endanger the safety of the coffer dams or cribs, provided that such forms are not visible in the finished structure. All other fromwork or falsework both above and below water level shall be removed.

3.4 Concreting

3.4.1 General

(a) No concrete shall be placed until the formwork and falsework has

been completed in accordance with clause 3.3.2 above and approved

by the Engineer. No concrete shall be placed without the approval of

the Engineer.

(b) Concrete may be mixed at the site of construction, at a central point,

by a combination of central point and truck mixing or by a

combination of central point mixing and truck agitating.

(c) All concrete shall be batched by weight unless otherwise directed by

the Engineer. The weight-batching machines shall be of a type

approved by the Engineer and shall be kept calibrated, accurate and

in good condition. Checks shall be made as required by the Engineer

to determine that the weighing devices are registering correctly. Each

mixer shall be fitted with a water measuring device having accuracy

within one percent of the quantity of water required for the batch.

The measuring device shall be such that its accuracy is not affected

by variations in the water supply pressure.

(d) Where aggregate batching by volume is permitted, each size of

aggregate shall be measured in a metallic container, the depth of

which shall be at least equal to its greatest width. The containers

shall be of such shape that their volume can be easily checked by

measurement. Cement shall be batched by weight and water by

weight or volume.

(e) The batching of concrete shall not begin until such time as all the

equipment and labour required for batching, transporting, placing,

compacting, finishing and curing the concrete is in place in

accordance with the Contractor’s approved method statement.

3.4.2 Batching

(a) Measurement and batching of materials shall be done at a batching

plant and all concrete shall be machine mixed.

(b) The Contractor shall submit his method statement for the batching

and mixing of concrete to the Engineer for his approval. The

statement shall include the location of the batching and mixing plant,

the type or types of mixers and machines to be used, arrangements

for the storage of aggregates and the batching and mixing of concrete

and transporting concrete from the batching plant to the site.

(c) The type of mixer shall be a drum mixer. Mixers of less than 0.5 cubic

meter capacity shall not be used to batch structural concrete. The


use of continuous mixers will not be permitted.

(d) The batching plant shall include separate bins for the bulk cement,

fine aggregate and for each size of coarse aggregate, a weighing

hopper, and scales capable of determining accurately the weight of

each component of the batch. Scales shall be accurate to one percent

throughout the range of use.

(f) If there is no prior experience with the approved mix design or if

special handling procedures, such as pumping, change of one or more

of the characteristics between discharge of the load and placing in the

forms, the Contractor shall correlate the discharge tests with the

placement tests to define these changes.

(g) The Contractor shall also provide documentation, repeat the

correlations as often as necessary or as directed by The Engineer.

(1) Portland Cement

(a) Either sacked or bulk cement may be used. No fraction of a sack of

cement shall be used in a batch of concrete.

(b) All bulk cement shall be weighed on an approved weighing device.

The bulk cement weighing hopper shall be properly sealed and

vented to prevent the escape of cement dust. The discharge chute

shall not be suspended from the weighing hopper and shall be so

arranged that cement will not lodge in it nor leak from it.

(c) Accuracy of batching shall be within 1 percent of the required

weight.

(2) Water

(a) Water may be measured either by volume or by weight. The

accuracy of water measurement shall be within one percent of the

required weight or volume.

(b) About 10 percent of the water required for the batch shall be

poured into the drum before the cement and aggregates, and the

remainder of the water shall be added uniformly while the drum is

in action and all the water shall be in the drum by the end of the

first quarter of the mixing time.

(3) Aggregates

(a) All aggregates produced or handled by hydraulic methods or that

have been washed shall be stockpiled or binned for draining at

least 12 hours before being batched. Where the moisture content

of aggregates is high or non-uniform, they shall be stored or

stockpiled for a period in excess of 12 subject to approval by the

Engineer.

(b) The accuracy of measurement of aggregates shall be within two

percent of the required weights.


3.4.3 Mixing and Delivery

(a) When mixed batches are hauled to the mixer, bulk cement shall be

transported either in waterproof compartments or between the fine

and coarse aggregates. Where cement is placed in contact with moist

aggregates, batches will be rejected unless mixed within 1.5 hours of

such contact. Bagged cement may be transported on top of the

aggregates.

(b) The concrete shall be mixed until a uniform colour and consistency is

obtained.

(c) Mixing and delivery of concrete shall be in accordance with the

requirements of ASTM C94 except where modified in this specification

for truck mixing or a combination of central point and truck mixing or

truck agitating. Delivery of concrete shall be so regulated that

placing is at a continuous rate unless delayed by the placing

operations. The intervals between deliveries of batches shall not be

so great as to allow the concrete in place to harden partially, and in

no case shall such an interval exceed 45 minutes.

(d) Any arrangements for the cooling of the mixing water as and the

handling of admixtures shall be subject to approval by the Engineer.

(e) Additional mixing water and/or admixture may not be added on the

Work Site unless specifically authorized by the Engineer and if the

water/cement ratio in the approved job mix is not exceeded and the

truck mixer is loaded to no more than 70 percent of its rated

capacity.

(f) The volume of concrete mixed per batch shall not exceed the mixer’s

nominal capacity as shown on the manufacturer’s standard rating

plate on the mixer. Water shall be added as required by clause 3.4.2

(2)b above.

(g) Mixing shall continue for the minimum times shown below after all the

water has been added.

mixers having a capacity of 1.5

m3 or less

minimum 60

seconds

mixers having a capacity greater

than 1.5 m3

minimum 90

seconds

mixer with a capacity of 750

liters or less

minimum 1.5

minutes

each additional 500 liter

capacity or fraction

be increased by

15 seconds

double-drum high performance

mixer

minimum 70

seconds


(h) Mixing time shall be measured from the time all materials, except

water, are in the drum.

(i) The timing device on stationary mixers shall be equipped with a bell

or other suitable warning device to give a clearly audible signal each

time the lock is released. If the timing device fails, the Contractor

may continue operations for up to 24 hours while it is being repaired,

provided he furnishes an approved timepiece equipped with minute

and second hands. After 24 hours the mixer shall not be used until

repairs are made.

(j) On cessation of work, including all stoppages exceeding 20 minutes,

the mixers and all handling plant shall be washed with clean water.

Any deposits of old concrete in the drum shall be cleaned out by

rotating clean aggregate and water in the drum before any fresh

concrete is mixed.

(k) Concrete that is not in place within one hour of the time when

ingredients were charged into the mixing drum, or concrete that has

developed an initial set, shall be rejected.

3.4.4 Concrete Consistency

The concrete slump shall be determined by the Contractor’s trial mixes and

shall be measured in accordance with AASHTO T119.

3.4.5 Pumping

(a) Placing of concrete by pump subject to the approval of the Engineer.

(b) Where concrete is conveyed and placed by pump, the equipment shall

be fit for purpose and of sufficient capacity for the work.

(c) The operation of the pump shall produce a continuous stream of

concrete without air pockets.

(d) When pumping is completed, If the concrete remaining in the pipeline

after completion of placing is to be used, it shall be ejected in such a

manner that there shall be no contamination of the concrete or

separation of the ingredients.

3.4.6 Placing and Compacting

(a) The Contractor shall include the method and sequence of placing

concrete in his method statement to be approved by the Engineer.

Concrete shall not be placed until formwork and reinforcement have

been approved by the Engineer has.

(b) Concrete shall be placed gently in position and shall not have a free

fall of more than 1.5m to avoid segregation of the materials and

displacement of the reinforcement.

(c) The use of pipes or chutes for transporting concrete shall not be

permitted without the approval of the Engineer.

(d) Where the use of pipes or chutes is permitted they shall be rubber or


metal. Where steep slopes are required chutes shall be equipped with

baffle boards or be in short lengths that reverse the direction of

movement. The use of aluminium chutes, tremie pipes, troughs, and

pipes will not be permitted.

(e) Pipes or chutes may be allowed for small sections and bottom dump

buckets or other suitable vessels may be allowed for large sections to

convey the concrete as near as possible to its final position.

(g) Concrete shall be placed so as to prevent water from collecting at the

ends, corners or along the faces of the forms, and water shall not be

placed in large quantities at a given point and allowed to run or be

worked over a long distance in the form.

(h) All concrete shall be placed and compacted in even layers with each

batch and each layer merged with the previous one.

(i) The thickness of concrete layers shall be between 15-cm and 30-cm

for reinforced concrete and up to 45 cm for none reinforced concrete.

(j) Concrete shall be compacted by mechanical or electromechanical

poker vibrators. Each immersion shall continue until shortly after air

bubbles cease to appear on the surface of the concrete, but shall not

last more than 30 seconds. Vibrators shall be withdrawn gradually

and vertically to ensure that no air pockets are formed. Over-vibration

of concrete will not be permitted. Vibrators shall not be in contact

with reinforcement in any circumstances. Vibrators shall not be used

to distribute concrete in the formwork.

(k) When required, vibrating shall be supplemented by hand spading with

suitable tools to assure proper and adequate compaction

(l) The Contractor shall provide stand-by vibrators during all concrete

pours. At least two vibrators shall be available at the site when more

than 25 m3 of concrete are to be placed.

(m) All vibration, compaction and finishing operations shall be completed

immediately after the placing of concrete in its final position.

(n) Concreting in any one part or section of the work shall be carried out

in one continuous operation and no interruption of work will be

allowed.

(o) Where beams and slabs together form an integral part of the

structure, they shall be poured in one operation, unless otherwise

specified or an approved provision is made to form a construction

joint.

(p) After a beam, wall or column has been cast, an interval of one hour

shall be allowed before casting the continuous slab. The same applies

for all abrupt changes in sections.

(q) During placing exposed concrete surfaces shall be worked by means

of tools of an approved type to force all coarse aggregate from the


surface, to bring mortar against the forms to produce a smooth finish,

substantially free from water and air pockets, or honeycombing.

Excessive working which produces layers of laitance on the surface

will not be permitted.

(r) Freshly placed concrete shall be adequately protected from rain, dust

storms, chemical attack and the harmful effects of sun, heat, wind,

flowing water, vibrations and shocks. It shall also be fenced off or

otherwise protected to prevent persons from walking thereon or

articles being placed or thrown thereon. This protection shall

continue until the concrete is sufficiently set such that it can no longer

be damaged by these factors. The protection shall not be less than 24

hours after the time of placing subject to the approval of the Engineer.

(s) The Contractor shall take all necessary precautions to prevent

differential temperatures across any concrete element from exceeding

20oC during concrete placing and curing.

3.4.7 Placing of Concrete in or Under Water

(a) The Contractor shall submit his proposed methods for placing

concrete in or under water to the Engineer for his approval before

proceeding with the work.

(b) The method of placing concrete in or under water shall be such as to

keep as much as possible the concrete being placed out of direct

contact with the water to avoid any rapid movement or agitation of

the exposed concrete surface.

(d) Tremie pipes shall be smooth bored, watertight, fitted with quick

release joints and have an adequate cross-section for the size of

aggregate to be used. Aluminium pipes shall not be used.

(e) Bottom opening skips shall be straight sided, smooth and fitted with

externally operated bottom opening double doors and overlapping

canvas flaps.

(g) Where concrete is to be placed in or under water, the actual mix

proportions and selection of aggregates shall be such as to ensure a

resulting concrete with good flow and cohesion characteristics.

(h) The cement content shall be 25 percent greater than for a

comparable mix for use in dry conditions. The minimum cylinder

strength for all concrete shall be approved by the Engineer for the

comparable mixes for use in dry conditions.

3.4.8 Weather Precautions

(a) During hot weather steps shall be taken to reduce the concrete

temperature. When the air temperature in the shade is 35oC and

rising, precautions shall be taken during all concrete operations so

that the temperature of the concrete when placed does not exceed

32oC.


(b) The concrete mixing plant shall be screened and covered to protect it

from the sun (and wind and rain). Similar precautions shall be taken

throughout the transit, placing and curing of the concrete whenever

conditions require them.

(c) Aggregates shall be shaded and mixing water shall be cooled and

other steps taken to the satisfaction of the Engineer.

(d) Fresh concrete placed at air temperatures of 35oC or higher shall be

shaded from the direct rays of the sun to the satisfaction of the

Engineer.

3.4.9 Continuity of Concrete Work

(a) The Contractor shall carry out the work in such a manner that the

placing of concrete in any particular section of the structure shall be

executed without any interruption whatsoever from the beginning to

the end of the operation. If interruptions occur, no fresh concrete

shall be deposited on or against the concrete placed before the

interruption such time as the concrete is sufficiently set to permit the

formation of a construction joint.

(b) Particular care shall be taken to ensure that partially set concrete

shall not be damaged by shock or any other cause whatsoever.

(c) To ensure continuity casting of concrete shall not commence until

sufficient approved material is at hand to ensure completion of the

operation and there is sufficient equipment in reserve for use in the

case of breakdown.

3.5 Joints

3.5.1 General

(a) Joints shall be limited to the positions indicated on the drawings and

shall be of the type specified.

(b) Expansion joints shall incorporate in their construction adequate

protection against the entry of debris or other material that may

interfere with the closing of the joints.

(c) Construction joints are detailed on the drawings which shall as a rule

be formed at right angles to the axis of the members.

3.5.2 Construction Joints

(a) Construction joints shall be made only at locations indicated on the

drawings or as specified herein, except in cases of breakdowns or

other unforeseen and unavoidable delays, in which case the a joint

shall be formed to the satisfaction of the Engineer.

(b) Construction joints in abutment walls, wing-walls, and barrels of box

culverts shall not be placed at intervals exceeding 10 meters except

as otherwise indicated on the drawings or as may be approved by the

Engineer.


(c) All joints which are exposed to view shall be carefully finished true to

line and elevation. After the header board has been removed, laitance

shall be removed from the surface by washing with water under

pressure or by sandblasting to expose clean, well bonded aggregate.

After the surface has been prepared, the concrete shall be left

saturated with water until the new concrete is placed, or it shall be

saturated for a period of 4 hours before placing the new concrete.

Shear keys or steel dowels shall be used where required. Shear keys

formed into the concrete shall be formed by the insertion and

subsequent removal of bevelled wood strips which shall be thoroughly

saturated with water prior to insertion. The size and spacing of the

keys and dowels shall be subject to approval by the Engineer.

(d) Care shall be exercised not to injure the concrete or break the

concrete-steel bond at any time. On bridge slabs workmen shall not

be permitted to stand or walk on the reinforcement until the concrete

has hardened. Suitable boards or platforms supported on the slab

formwork shall be provided for access during casting.

3.5.3 Bonded Construction Joints

Except where otherwise specified, bonded construction joints shall be

made using any of the following procedures, as appropriate.

(a) After the header board has been removed, laitance shall be removed

from the surface by washing with water under pressure or by

sandblasting to expose clean, well bonded aggregate. When the

concrete has been cured for the normal period, the second pour shall

be bonded to the first pour by the application of a two-component

liquid polysulphide polymer epoxy resin concrete adhesive to the

concrete joint surface. The epoxy concrete adhesive shall be subject

to approval by the Engineer.

(b) The surface on which the adhesive is to be applied shall be free of oil,

dirt, and loose concrete. All unsound concrete shall be removed until

a base of strong, undamaged concrete on which to apply the adhesive

is exposed. Heavy deposits of dirt or oil products shall be removed by

wire brushing or sandblasting. The surface shall be free of moisture

and dry before application of the adhesive.

(c) Immediately before application, the two adhesive components shall

be combined in the proportions and to the methods specified by the

manufacturer. All components shall be fully blended. The amount of

adhesive mixed at one time shall be limited to that quantity which can

be conveniently applied within the pot life indicated by the

manufacturer.

d) The resulting adhesive shall be applied to the concrete in accordance

with the manufacturer’s recommendations. Concrete shall not be

placed against the joint until the adhesive has become tacky or


otherwise recommended by the manufacturer. Areas that have been

allowed to dry shall be recoated before concrete is placed.

(e) Adhesives may be toxic or otherwise injurious to health or otherwise

be classified as hazardous materials. The Contractor shall obtain from

the manufacturers of the materials complete instructions as to the

health and safety precautions that must be exercised with respect to

the materials to be used, and as to the procedure that shall be

followed in the event that workmen come in contact with such

materials. Before they are permitted to proceed with the work,

workmen shall be instructed on the hazards to which they will be

exposed, the necessary safety precautions and the procedure to be

followed in the event of accidental contact with the materials.

3.5.4 Joint between the deck slab and the coping.

The joint between the deck slab and the coping shall be de-bonded using an approved elastic material which shall allow movement between the slab and the coping. The Contractor shall submit his proposal for the provision and placing of the de-bonding layer to the Engineer for his approval.

3.6 Concrete Finishing

3.6.1 Finishing Concrete Surfaces

All concrete surfaces shall be finished as indicated on the drawings or as

otherwise approved by the Engineer.

(a) Permanently exposed concrete surfaces to Class F4, F3 and F2 finish

shall be protected from rust marks and stains of all kinds.

(b) Unless otherwise described in the Specifications, all formwork joints for

exposed surfaces of concrete to Class F2, F3 and F4 finish shall form a

regular pattern with horizontal and vertical lines continuous

throughout each structure and all construction joints shall coincide

with these horizontal or vertical lines.

(c) The types of surface finishes and necessary form works are as follows:

Table 5:Type of Concrete Finishes

Finishing Description Formworks

Formed Finish

Class F1No particular requirements for finishing

Sawn Formwork for unexposed concrete surfaces

Class F2With specified regularities on the finish

Wrought Formwork of steel or plywood or timber.

Class F3

With accurate finishing to provide a smooth finish of uniform texture and appearance

Lined Formwork using material approved by the Engineer to be of the same type and obtained from one source throughout for any one structure.

Class F4With accurate finishing on the use of internal ties and embedded metal parts

Unformed Finish

Class U1 Leveled by wooden float etc. -Class U2 Steel float finishing


Class U3 Finishing by steel-trowel 3.6.2 Remedial Treatment of Finished Surfaces

(a) Any remedial treatment to finished surfaces shall be agreed with the

Engineer following inspection immediately after removing the

formwork and shall be carried out without delay.

(b) Any concrete the surface of which has been treated before being

inspected by the Engineer will be liable to rejection.

3.6.3 Fixing of Ironwork

All brackets, lag-bolts and other ironwork for which holes have been boxed

out or left in the concrete of a structure shall be carefully grouted into their

correct positions. 3.6.4 Reconstruction of Faulty Work

In the event any members or portion of the work proves, after removal of

the formwork, to be of inferior workmanship or to be in any way

whatsoever defective, or should crushing tests on samples taken from the

work show that the concrete used therein is of inferior Quality, such work

shall, at the discretion of the Engineer, be cut out and replaced.

3.7 Curing

(a) All newly placed concrete shall be cured. Curing shall begin

immediately after finishing and continue for at least 7 days. Curing is

required to prevent drying out of the concrete and shall be considered

an integral part of the concreting operations.

(b) Improperly cured concrete will be considered defective. Concrete work

will not be permitted to continue until proper procedures are put into

effect by the Contractor.

(c) Curing of concrete shall be included in the Contractor’s method

statement and shall be subject to the approval of the Engineer. The

methods detailed below may be used.

(c) Timber formwork covering the concrete shall be moistened with water

at frequent intervals to keep it from drying during the curing period.

Metal formwork exposed to the sun must be shaded from its direct rays,

painted white or otherwise protected during the curing period.

(d) When forms are removed before the end of the 7-day curing period,

specified curing procedures shall be applied by the Contractor and

continued until the end of the 7-day period as specified.

3.7.1 Methods using water

Surfaces may be kept moist by ponding, sprinkling, or fogging. Coverings

such as burlap shall be used to retain water so supplied. The use of

sawdust will not be allowed and coverings that cause unsightly

discoloration of concrete shall not be used. Any method that results in the

concrete being alternately wet and dry will be considered an improper


curing procedure. Coverings shall be placed as soon as possible after

finishing operations have been completed and there is no danger of

surface damage. The coverings shall be kept continuously moist. 3.7.2 Preventing Moisture Loss

Moisture loss may be prevented by the use of approved waterproof paper,

plastic sheets, or liquid membrane curing compound except where other

requirements prohibit the use of these compounds. If a formed surface is

to be rubbed, the concrete shall be kept moist before and during the

rubbing, and the curing shall be initiated immediately following the first

rub while the concrete surface is still moist. 3.7.3 Waterproof Paper

The paper shall have the widest practicable width and adjacent sheets

shall overlap a minimum of 15 cm and shall be tightly sealed with a

pressure sensitive tape, mastic, glue or other approved methods to form a

complete waterproof cover of the entire concrete surface. The paper shall

be secured so as not to be displaced by wind. If any portion of the sheets

is broken or damaged before expiration of the curing period, the broken or

damaged portion shall be immediately repaired. Sections that have lost

their waterproof qualities shall not be used. 3.7.4 Plastic Sheets

The sheets shall be used in the same manner as required above for

waterproof paper. 3.7.5 Curing Compounds

(a) Curing compounds shall not be used on areas receiving a rubbed

finish. Only Type 2 liquid membrane curing compound complying with

AASHTO M148 may be used subject to approval by the Engineer.

Curing compounds shall be applied to unformed areas as soon as the

water sheen has practically disappeared from the concrete, or as soon

as the forms have been removed from surfaces. If there is any

expected delay in applying curing compound, the surface shall

receive moist curing until the compound can be applied.

(b) All curing compounds shall be thoroughly agitated just prior to use

and shall be applied with equipment that will produce a fine spray.

The compound shall be applied in two coats sprayed at right angles to

each other. The rate of each application shall be not less than 1 liter

for each 3.6 square meters of surface or as detailed in the

manufacturer’s information.

(c) Care shall be taken to prevent application to surfaces where a

concrete bond is required, and to joints where joint sealer is to be

placed. If the membrane film is broken or damaged at any time

during the curing period, the broken or damaged area(s) shall be re-

coated according to the original requirements.


3.8 Precast Concrete

(a) Pre-cast concrete elements shall be provided as detailed in the

drawings.

(b) The Contractor shall provide and install all pre-cast elements complete,

furnishing all materials, labour and equipment and performing all

required work as required by drawings, as specified herein, other

applicable Specification Sections and as may be required by the

Engineer.

(c) The pre-cast constituents and component work shall include, but not be

limited to, the supply and installation of the pre-cast elements,

necessary grout and grouting and all appurtenances required for their

proper installation.

3.8.1 Materials

(a) Concrete materials incorporated in the fabrication of pre-cast elements

shall comply with the applicable requirements of this section of the

specification as well as other applicable Specification Sections and shall

be of the class of concrete as noted on the drawings or as may be

required by the Engineer.

(b) Grout shall be an approved, free flowing, non-shrink, non-metallic grout

containing sulphate resistant cement. The grout shall have a minimum

28 day compressive strength of 20 MPa when tested in accordance with

appropriate sections of ASTM C109. The grout shall show no expansion

after the final set takes place when tested in accordance with ASTM

C827 or an equivalent test method that may be approved by the

Engineer. The grout shall have an initial setting time of not less than 45

minutes.

3.8.2 Fabrication

(a) T girders shall be cast horizontally.

(b) The dimensional length of beams shown on the drawings is the required

length including allowances for elastic shortening creep or shrinkage.

(d) To ensure proper bond to the deck slab, the top surface of girders in

contact with deck slabs shall be given a rough exposed aggregate

finish. At approximately the time of initial set, all laitance shall be

removed with a coarse wire to expose the concrete aggregate.

(e) Pre-cast elements that are manufactured off-site shall not be

transported from the fabrication area until the concrete has achieved

its 28 day strength.

(f) All pre-cast members shall be lifted and supported only at the points

indicated on the drawings or as may be otherwise approved by the

Engineer.

(g) Pre-cast items shall be lifted and handled to in such a way that no

damage occurs. Any damage to pre-cast items that occurs during


transportation or placement shall be inspected by the Engineer. The

Engineer may reject damaged pre-cast items if, in his opinion, such

damage will adversely affect the strength or the appearance of pre-cast

items.

3.9 Quality Control of Concrete

3.9.1 General

(a) The quality control of concrete shall be included in the Contractor’s

Quality Assurance scheme for the entire Project. The Contractor shall

make particular reference to the target mean strength of the concrete

in his quality scheme and shall describe clearly all factors relevant to

its determination.

(b) All Quality control tests must be carried out in a manner acceptable to

the Engineer and shall be conducted by an Independent Laboratory or

the Contractor’s laboratory on Site.

3.9.2 Technicians at Mixing Plant

(a) The Contractor shall designate a competent and experienced concrete

technician to be in charge of the mixing plant and to be responsible

for quality control including, but not limited to, the following:

(i) The proper storage and handling of all components of the mix.

(ii) The proper maintenance and cleanliness of plant, trucks, and other equipment.

(iii) The gradation testing of fine and coarse aggregates.

(iv)

The determination of the fineness modulus of fine aggregate.

(v) The measurement of moisture content of the aggregates and adjustment of the mix proportions as required before each day's production or more often if necessary to maintain the required water/cement ratio.

(vi)

The computation of the batch masses for each day's production and the checking of the plant's calibration as necessary.

(b) He shall be assisted by at least one competent and experienced

concrete technician at the project site responsible for concrete

sampling and testing during placing of concrete.

(c) He shall ensure furnishing on behalf of the Contractor of all equipment

and the performance of temperature, unit mass, slump, and other

tests to verify compliance with the specification before and during

each placement operation.

(d) He shall verify that adjustments to the mix before discharge comply

with the specifications.

(e) He shall ensure completion of the batch ticket, which shall include the

detail below, the recording of the apparent water/cement ratio, and

the time discharge are completed; furnishing a copy of each batch

ticket at the time of placement.


Concrete supplier

Ticket serial number

Date and truck number

Contractor

Structure or location of placement

Mix-design and concrete class

Component quantities and concrete total volume

Moisture corrections for aggregate moisture

Total water in mix at plant

Time of batching

Time at which discharge must be completed

(g) Ensure testing to determine the unit mass, slump, and temperature

according to this specification.

(h) The provision of copies of work sheets and test results as they are

completed.

3.9.3 Sampling of Mixed Concrete

(a) The frequency of sampling and testing shall be included in the quality

control plan for concrete and subject to the approval of the Engineer.

(b) Samples shall be taken from each work item or batch as in the

Contractor ‘s approved quality control plan and in accordance with

AASHTO-T141. The temperature and slump of the concrete shall be

tested for each load at discharge or at such frequency as may be

approved by the Engineer. Test will not be deemed to have been

carried out unless witnessed by the Engineer or his representative.

The method of making the slump test shall conform to ASTM C143.

(c) Sampling at discharge shall be after at least 0.2 cubic meters are

discharged and before placing any of the batch in the forms.

(d) The initial testing frequency shall be resumed if a test shows a failing

temperature or slump or when required by the Engineer.

(e) The Contractor shall bear all expenses for obtaining, cutting out or

sampling all specimens and/or component parts for testing.

3.9.4 Compressive Strength Testing

(a) Testing to determine the compressive strength of concrete shall be

used for the following purposes:

* to allow early stripping of forms.

* permit the application of post tensioning force.

* permit the launching of the traveller.

* acceptance of the completed work

(b) The procedure for strength testing shall be in accordance with ASTM


C1077 or an equivalent procedure approved by the Engineer.

(c) The Contractor’s quality control plan shall include details of his

proposed procedure for the determination of early concrete strengths.

This procedure shall use conventional test cylinder results to

substantiate strength predictions for each class and location of

concrete pours. The figure below is an example of an acceptable the

procedures.

3.10 Testing frequencies

Testing frequencies shall be accordance with Vietnamese Standard: TCVN 4453-95; TCXDVN 305-04 or other international standard subject equivalence being demonstrated by the Contractor and the satisfaction of the Engineer of the Vietnamese standard shall apply:

Item Test Description Test Frequency

Remark

1 TCVN 4453-95: Monlithic concrete and reinforced concrete structures – Codes for construction, check and acceptance.

a

Material testing & preparation work before construction: (for material & quarries approval)

+ General requirement Article 5.1 + Cement Article 5.2

+ Sand Article 5.3 + Quality of aggregate for concrete Article 5.4 + Water for concrete : Article 5.5

Volume 3 – Technical Specification Concrete and Concrete Structures

9 Specimens by Cylinder from each 100 cubic meters of concretewhen the same grade is used continuously, or as directed by the Engineer

3 Samples from Cylinder numbers 2&8, 3&7, 4&6

7 days compressive strength test

Countermeasures to be taken

Cylinder numbers 1, 5 and 9

28 days compressive strength test

if less than X%* from required 28 days compressive strength

stop placing concrete

and rectify any defect

Remove and replace the defective concrete without waiting the results of 28-day test by the responsibility of the Contractor

OK

OK

Example of Concrete Strength Quality Control Flow Chart

Acceptance of the Lot

if No

*Note: This percentage or strength shall be decided in accordance with the test results of trial mixing as mentioned in sub-section 3.1 Concrete Mix Design and with the proposal by the Contractor.

Alternative 1

Alternative 2

- 31 -

+ Others requirement index for concrete ; additive cement … Article 5.6; 5.7

+ Formworks and falsework Article 3

+ Reinforcement for concrete Article 4 b During construction period: Article 6

( Note: Article 6.8 has been superseded by TCXDVN 305:2004)

cAfter construction period: (For acceptance of construction works)

Article 7 : Table 19

2TCXDVN 305-04: Mass concrete – Code of practice of construction and acceptance

a

Material testing & preparation work before construction: (for material & quarries approval) Article 6.9.1

+ Cement : Article 6.2.1

+ Quality of aggregate for concrete (include sand): Article 6.2.2

+ Water for concrete : Article 6.2.3

+ Others requirement index for concrete chloride ion, additive cement : Article 6.2.4

b During construction period: Article 6.4 ; Article 6.9.2


Article 6.9.3 ; Article 7

3.11 Acceptances Test and Tolerances

3.11.1 Strengths

(a) Final acceptance of concrete work will be based on 28 day tests for

compressive strength testing and the dimension of the completed

works.

(b) The work is considered in compliance if the average of the samples

equals to or exceeds the minimum specified strength for the class of

concrete being placed.

(c) If the results of the 28-day tests do not satisfy the minimum technical

requirements the Contractor shall conduct such additional test as

may be required by the Engineer.

(d) If the concrete does not comply with the specifications, the Engineer

may order the Contractor to remove the defective concrete and

replace it with concrete of the specified Quality. All additional testing

and remedial work shall be at the expense of the Contractor.

(e) At the discretion of the Employer and subject to there be no risk to

the completed structure the Employer may accept a reduced

payment for work which is not in compliance with the specification.

Any such reduced payment will be determined by the Engineer in co-

operation with the Employer.

3.11.2 Dimensions

(a) The finished dimensions of concrete structures shall be as shown on


Table 6.

Table 6 Dimension TolerancesFooting Pile cap

Pier column

Bearing Pedestal

Wing wall ApronApproach

SlabConcrete Railing

Top Level ±10 mm ±5 mm ±2.5 mm ±5 mm ±5 mm ±5 mm -

Center

Position±5 mm ±5 mm ±5 mm - - ±5 mm ±5 mm

Dimension －10 to +50 mm* -

Verticality - ±1/300 - ±1/ 300 - - ±1/500

Top Grade

Irregularities- - 1 in 200 -

±2.5 mm

in 3 m

±5 mm

in 3 m

±3 mm in 3

m (1/1000)

Wall Flatness - - - ±5 mm - - -

4. MEASUREMENT AND PAYMENT

4.1 Method of Measurement

(a) Each class of concrete shall be measure separately in cubic metres and

measurement shall be made to the lines of the structures as indicated

on the drawings and as described in the Bill of Quantities. No deduction

shall be made for the volume of chamfers, the volume of reinforcement,

the volume of boxouts or the volume of items cast in concrete.

(b) Acceptance of concrete structure shall be based on compliance with

particular sections of the specification that might apply to the

structure.

4.2 Basis of Payment

(a) The accepted quantities, measured as provided above, shall be paid at

the contract price per unit of measurement for the pay items of the Bill

of Quantities listed below. However payment may be adjusted as stated

in clause 3.10.1(e) above.

(b) At the discretion of the Engineer a payment of 90% of the bill item may

be included in a certificate for concrete which has been completed in an

otherwise satisfactory manner but for which the final curing is not

complete or the test for the 28 days compressive strength could not be

completed.

(c) No separate measurement or payment shall be made for the Formwork

and falsework. They shall include but not be limited by the items listed

below and shall be deemed included in the applicable items of the Bill

of Quantities.

* all expenses involved in providing, pumps, cofferdams, braced sheet piling or any other methods approved by the Engineer;

* all expenses resulting from the Contractor’s observance of all rules and regulations of competent authorities regarding the interference or maintenance of flow in the relevant canals,


water courses, channels or pipes;

* provisions for placement and removal of temporary Jetty/Guide frames;

* provisions for travellers and traveller testing

* provisions for underwater works;

* provisions for underwater concrete;

* previsions for pumps and de-watering by submersible pumps;

* provisions for all necessary barges; and

* provisions for all necessary tugboats and auxiliary river craft.

* furnishing all labour, materials, tests, tools, equipment and any incidentals to complete the work as shown on the Drawings and as required by these Specifications, and/or as directed by the Engineer

Pay Item Description Unit

07100-01 Concrete Class C50 MPa m3

07100-02 Concrete Class C 35 MPa m3




07100-06

07100-07

Concrete Class C 10 MPaBlinding crush stone

m3

m3


SECTION 07200 - PRECAST CONCRETE PILES

TABLE OF CONTENTS

1. DESCRIPTION....................................................................36

2. MATERIAL REQUIREMENTS.................................................362.1 Reference Standards.....................................................................362.2 Materials for Piling........................................................................36

2.2.1 Supply of Material...........................................................................................362.2.2 Concrete.........................................................................................................362.2.3 Reinforcing Steel.............................................................................................36

3. CONSTRUCTION REQUIREMENTS........................................373.1 Submittals....................................................................................373.2 Requirement of Pile Works.............................................................373.3 Casting, Curing and Finishing........................................................383.4 Handling.......................................................................................383.5 Pilot Piles.....................................................................................383.6 Driving and Pile Construction.........................................................393.7 Pile installation by static pressing method (TCVN 286-20003 section 6)

403.8 Pile Splicing..................................................................................423.9 Defective Piles..............................................................................433.10 Pile Records..................................................................................43

4. MEASUREMENT AND PAYMENT...........................................434.1 Measurement and Payment............................................................434.2 Basis of Payment...........................................................................44

Volume 3 – Technical Specification Pre-cast concrete Pile- 35 -

1. DESCRIPTION

(a) This Section specifies the materials and workmanship for fabrication,

installation and testing of pre-cast reinforced concrete piles.

(b) The types of piles to be used shall be as indicated on the drawings. The

Contractor propose to use an alternative type of pile, in which case he

shall provide the Engineer with information on the design data, piling

experience, records, and calculations supporting the pile design. All

such proposals shall be subject to approval by the Engineer.

2. MATERIAL REQUIREMENTS

2.1 Reference Standards



ASTM D1143

Test Method for Piles Under Static Axial Compressive Load

In addition all materials and procedures shall comply with the requirements

of the relevant of ASTM standard in its latest edition, or other national

standard specifications which may be approved by the Engineer.

2.2 Materials for Piling

2.2.1 Supply of Material

The Contractor shall submit to the Engineer for his approval, samples of the

material to be provided and the names of the manufacturers and suppliers

who will supply the materials required for pile construction. The Quality of

the material provided shall be certified by the supplier, and samples shall

be tested under the supervision of the Engineer, at the Contractor’s

expenses. 2.2.2 Concrete

The concrete class to be used for pre-cast piles shall be as indicated on the

drawings and shall comply with the requirements of Specification -

Concrete and Concrete Structures. 2.2.3 Reinforcing Steel

The reinforcement steel to be used for pre-cast piles shall be as indicated

on the drawings and shall comply with the requirements of Specification -

Reinforcing Steel.



3.1 Submittals

The Contractor’s proposed method statement for pre-cast concrete piles

shall be submitted to the Engineer for his approval well before the start of

pile driving. The method statement shall include but not necessarily limited

to the following:

① The location and extent of necessary temporary works such as roads and bridges to be used to transport materials and equipment to the pile driving sites.

② Initial driving criteria to reach the bearing strata and design pile capacity.

③ The methods to be used for the precise location of the piles (geodetic positioning method and equipment) in accordance with the Drawings.

④ Method of controlling groundwater.

⑤ Anticipated ground vibration, ground movement and groundwater drawdown and method of instrumentation and monitoring.

⑥ Details of construction plant.

⑦ Full details on all driving equipment and methods, including kind of hammer, (gravity hammers, single and double acting steam or pneumatic hammers, or diesel hammers)

⑧ Method of pile Fabrication and transportation .

⑨ Method and sequence of excavation.

⑩ Method and sequence of pile installation, including methods of avoiding damage to adjacent piles, utilities and structures.

⑪ Calculations of driving stresses (both tension and compression) within acceptable limits for each proposed pile driving method

⑫ Method of jointing and lengthening piles

⑬ Details of advance any test piles and arrangements for pile testing

⑭ Calculations of the required final set

⑮ Drop height for the proposed piling hammer, to support the ultimate load of test piles in accordance with the specified settlement criteria.

3.2 Requirement of Pile Works

(a) Where required as stated on the drawings pile length and allowable

bearing capacity shall be verified by the Contractor and shall be

subject to the approval of the Engineer based on the results of any pile

tests required and the available subsoil information. A factor of safety

of (FS) equal to 2.5 shall be used or such FS which may be approved by


the Engineer.

(b) Where required by the Engineer and subject to agreement by the

Engineer, an allowance for soil settlement shall be added to the design

load before determination of the pile length and bearing capacity.

3.3 Casting, Curing and Finishing

(a) Formwork for pre-cast piles shall conform to the general requirements

for concrete formwork in the Specification for Concrete and Concrete

Structures

(b) The piles shall be cast in a horizontal position.

(c) Special care shall be taken to place the concrete to produce a pile free

from any air pockets, honeycombing or other defects.

(d) Concrete shall be placed continuously and shall be compacted by

vibration or by other means satisfactory to the Engineer.

(e) Forms shall be watertight and shall not be removed until at least

twenty four hours after the concrete has been placed.

(f) Curing of concrete piles shall be in accordance with Specification -

Concrete and Concrete Structures.

(g) Concrete strength of shall be confirmed by the quality control

procedures in Specification - Concrete and Concrete Structures.

(h) Each face of the pile shall not deviate by more than 6 mm over a

length 3 m determined by using straight edge placed on each face.

(i) Straightness shall be within 1/500.

(j) Piles shall not be driven less than 28 days after casting or such reduced

time as may be approved by the Engineer.

3.4 Handling

(a) Only accepted piles with satisfactory concrete strength and dimensions

shall be allowed to be driven.

(b) Concrete piles shall only be lifted by slinging from the lifting holes or in

positions which have been submitted to and approved by the Engineer.

(c) When lifting or transporting pre-cast concrete piles the Contractor shall

provide slings and all other equipment necessary to prevent any

appreciable bending of the piles and subsequent damage to the

concrete. Piles shall be so handled at all times to prevent breaking or

chipping of the edges.

(d) Piles damaged during handling or driving shall be replaced.

3.5 Pilot Piles

(a) Where test piles are required as indicated on the drawings or as may

be required by the Engineer they shall be driven prior to the driving of

permanent piles and in numbers and locations subject to approval by


the Engineer and based on conditions on site.

(b) Test piles shall be driven with the same hammer, driving cap, and dolly

and packing materials that are used for driving foundation piles.

(c) The Contractor shall keep a complete driving record of each test pile in

a form acceptable to the Engineer and complete with all data on the

piles including, but not limited to, hammer speed, operating stroke,

blows per 30 cm and final resistance.

(d) Permanent piling works shall not commence until the construction and

records of the test piles have been approved by the Engineer.

3.6 Driving and Pile Construction

(a) No work shall commence without the Engineer’s approval of the results

of test piles.

(b) All piles shall be driven in the presence of the Engineer or his

representative.

(c) If during pile driving, conditions indicate that a pile is hitting an

obstruction before reaching proper bearing stratum, the Contractor

shall drive through the obstruction or shall use whatever means to

remove or circumvent the obstruction, without additional cost to the

Employer.

(d) All excavation for piled foundations shall be complete before the piles

are driven. The excavation shall be to such an elevation as to

compensate for possible uplift or subsidence of the surrounding earth.

(e) The Engineer shall inspect all temporary structures, equipment and

facilities before their use. The Contractor shall at all times provide

required maintenance and repairs to keep these items in a safe and

serviceable condition.

(f) The methods used for driving piles shall not subject them to excessive

and undue abuse that produces crushing and spalling of the concrete.

Manipulation of piles to force them into proper position, if considered

by the Engineer too excessive, will not be permitted.

(g) Driving of piles with followers shall be avoided if practicable and shall

be done only with the approval of the Engineer.

(h) The pile tops shall be protected by driving heads, caps or cushions in

accordance with the recommendation of the manufacturer of the pile

hammer and to the satisfaction of the Engineer.

(i) The driving head shall keep the pile and the hammer on the same axis

to provide a driving surface normal to the top of the pile. The helmet,

dolly and any packing shall be in sound condition.

(j) The hammer blow shall be in line with the pile axis and the impact

surface shall be flat and at a right angle to the pile and hammer axis.


(k) The hammer shall be in good condition and operate correctly to deliver

adequate energy per blow,.

(l) The top of foundation piles shall be embedded in the concrete footing

as shown on the drawings. Piles shall be cut off such that 150 mm of

pile is embedded in the footing or foundation. The longitudinal

reinforcement of piles shall be embedded in the footing or foundation

to the length shown on the Drawings.

(m) The Contractor shall temporarily suspend pile driving operations and

report to the Engineer whenever the following conditions occur:

* There is a sudden change in the penetration rate of the pile.

* The pile has been suddenly deflected or otherwise moved.

* The top of the pile has been seriously damaged.

(n) All piles pushed up by the driving of adjacent piles or any other cause

shall be re-driven.

(o) Each pile shall, after being driven, be within a tolerance of 75 mm in

any direction from the locations shown on the drawings subject to

approval by the Engineer.

(p) When water jets are approved for use, the number of jets and the

nozzle volume and pressure shall be sufficient to freely erode the

material adjacent to the pile. The plant shall have sufficient capacity to

deliver at all times a pressure equivalent to at least 690 kPa at two

19mm (3/4 inch) jet nozzles. The jets shall be shut off before the

required penetration is reached and the piles shall be driven solely by

hammers to final penetration as required by the Engineer. Water jets

shall not be used during penetration of the bearing stratum.

If the pile driving is not permitted due to environmental restrictions. The

contractor shall consider other alternative construction method, to be

approved by the Engineer. One of the methods can be pile pressing as

follows:

3.7 Pile installation by static pressing method (TCVN 286-20003 section 6)

(a) The selection of pile pressing equipment must meet the following

requirements:

- power of the equipment shall not be less than 1.4 times the maximum pressing force in the design;- pressing force of the equipment must be applied on the central axis of the pile when pressing from the pile top and act uniformly on the sides of the pile when pressing to the side, the pressing force shall not create lateral force on the pile;- the equipment must have valid testing certificates for the pressure meter and the oil valve and a jack adjustment table issued by the relevant Authority.;


- pile pressing equipment must ensure the operation condition and labour safety during the construction.

(b)The selection of the counter-weight system for the pile pressing should be based on the site conditions, construction characteristics, geotechnical conditions and the capacity of the pressing equipment. Counter weight can be provided by ground anchors, kentledge or by the use of appropriate anchors placed in the foundations of the structure. In all cases, the total weight of the counter weight system shall not be less than 1.1 times the maximum pressing force in the design.

(c) When using the structure for counter weight the commencement of

pressing must be determined based on the condition of the structure:

acceptance of the structure and anchors in accordance with acceptance

procedures for reinforced concrete and the total loading of the anchor

system.

(d) The positioning and balancing of the pile pressing equipment must be checked as follows:- the axis of the force generating equipment must be coincident with the central axis of the pile,- the working plane of the floor of the pressing equipment must be horizontal and shall be checked by a spirit level or other means, - pressing plane of the force generating equipment must be vertical and perpendicular to the working floor;- the equipment must be tested to check the stability of the entire system by applying loading equal to the pile design loading plus an additional 10 - 15%.

(e) The pile tip location shall be checked in two planes perpendicular to each other and the centre shall not deviate from the design position by more than 10 cm. in either direction. The force exerted on pile shall be increased gradually so that the penetration speed does not exceed 1cm/s. If the pile becomes inclined, pressing shall stop and appropriate adjustments shall be made.

(f) Press any subsequent pile extensions as follows: The surface of the ends of the two pile sections must be made flat and

the connection details must be checked. Install the pile extension into the pressing location so that the axis of the centreline of the extension coincides with the pile tip axis and the inclination with the vertical axis does not exceed 1%;

The connection must be as required in the design. Surcharge the pile extension with the pile design loading plus an additional 10 – 15% during the connection process to create the bond between two concrete faces;.

Gradually increase the pressing force so that the penetration of the piles into the soil reaches a maximum of 2cm/s;

Pressing of the pile into stiff plastic clay should not stop for too long (due to connecting extensions or changing shifts…).

(g) A sudden increase in the pressing force may be due to the following:


- penetration of the pile tip into a stiffer soil layer;- the pile tip hitting an unforeseen object;- the pile has inclined sufficiently to hit an adjacent pile. In such cases suitable action must be taken which might be as follows: - if the pile is broken or inclined out of tolerance, it must be removed and re-pressed or an additional pile must be driven subject to instruction from the designer:- if an unforeseen object, dense sand or stiff clay are encountered, a guiding bore or high pressure water technique may be used.

(h) Pile pressing shall be considered completed when both of the following conditions are satisfied:

the pile length pressed into the ground is within the range of Lmin Lc Lmax, where: Lmin and Lmax are the minimum and maximum length of the designed pile based on the forecast of ground movement in the area and Lc is the pile length actually pressed into the ground;

pressing force prior to termination is within the range of (Pep) min (Pep)KT (Pep)maxwhere : (Pep) min is the minimum pressing force in the design; (Pep)max is the maximum pressing force in the design; (Pep)KT is the pressing force at time pressing stopped; this pressing force must be maintained with the penetration speed not exceeding 1cm/s for a depth not less than 3 times the pile diameter or pile width as appropriate.If the two above conditions are not met, the Contractor shall report to the Designer for the treatment method.

(i) The pile log shall record the pressing force for every metre of pile length until (Pep)min is reached; thereafter the pressing force shall be recorded for every 20 cm until termination or as directed by the Engineer or Designer.

3.8 Pile Splicing

(a) Full-length piles shall be used where practicable. Splicing of piles when

permitted shall be in accordance with the provision described in this

specification. All piles shall be continuously driven unless otherwise

allowed by the Engineer.

(b) The Engineer may approve any proposed splice joint if technical

requirements are properly satisfied.

(c) Any proposed splice joint shall be of a proven design with ultimate

compression, tension and bending capabilities at least equal to the

adjacent concrete section.

(d) The splice joint shall not be closer than eight (8) meters to the

underside of the pile cap.

(e) Before the Engineer approves any splice joint, lateral-bending tests of

the proposed joint shall be performed to the satisfaction of the

Engineer.

(f) Curing and finishing of extensions shall be the same as for the original

pile.


3.9 Defective Piles

(a) Any pile delivered with defects, or damaged during driving due to

internal defects or by improper driving, or driven out of its proper

location shall be corrected at the Contractor’s expense by one of the

following methods subject to the approval of the Engineer.

* The pile shall be withdrawn and replaced by a new and longer pile

where necessary.

* A second pile shall be driven or cast adjacent to the defective pile.

* The pile shall be spliced or built-up as otherwise provided in this

specification or the underside of the footing lowered to properly

embed the pile.

(b) A concrete pile shall be considered defective if it has a visible crack on

all four sides of the pile, or any defect which, in the opinion of the

Engineer, affects the strength of the pile.

(c) When a new pile is driven or cast to replace a rejected one, the

Contractor shall, at his own expense, enlarge the footing as deemed

necessary by the Engineer.

3.10 Pile Records

(a) The Contractor shall keep records of all piles driven or installed in a

form approved by the Engineer. A copy of the records shall be given to

the Engineer within two days after each pile is driven.

(b) The pile records shall give full information on the following:

Pile type and dimensions. Date of casting and concrete QualityDate of drivingDriving equipment: type, weight and efficiency of hammer, type and condition of driving head, cap, cushion, etc. Depth driven, ground elevation and tip elevationLevel of pile top immediately after driving and the level when all piles in the group are driven. Pile cut-off elevation. Penetration along the whole depth driven for every 10 piles, and when the Engineer so requires,. The height of drop: for gravity and single-acting hammers The frequency of blows: for double acting-hammersDetails of any interruption in driving. Details of re-driving.


4.1 Measurement and Payment

(a) The quantity of pre-cast concrete piles to be paid for shall be measured

by linear meters of the accepted and driven piles in place in the


completed and accepted work. Payment shall not be made for

unaccepted piles even if the pile was driven.

(b) Measurements shall be made from the tip (bottom of the steel shoe

plate of the pile) to the cut-off line indicated on the drawings or as may

be approved by the Engineer. Portions of piles cast deeper than

required through over-driving procedures shall not be measured for

payment.

(c) All the tests that may be required by the Engineer for approval of the

works, or the equipment, shall not be measured for separate payment,

and shall be considered as incidental work and shall be deemed

included in the rates and unit price of the piles.


(a) Payment for driven Pre-cast Concrete Piles, approved by the Engineer,

shall be made in accordance with the applicable Unit Prices of the Bill

of Quantities listed below. Payment shall be full compensation for

furnishing all labor, materials and equipment and performing all work

to complete the driven concrete pile foundations including but not

limited to, furnishing of reinforcement, excavation, hardware,

formwork, pile splicing, concrete, equipment, removal of remaining

material, disposal of rejected piles or materials, any kind of incidental

work, and all necessary appurtenances to complete the work.

(b) No separate payment shall be made for the pilot piles.

Pay Item

Description Unit

07200-1 Driven Precast Piles (250 mm x 250 mm) lm


SECTION 07250 - BORINGS FOR PILE BEARING CAPACITY- B ORED PILES

TABLE OF CONTENTS

1. DESCRIPTION....................................................................46

2. REFERENCE STANDARDS...................................................46

3. SOIL INVESTIGATION BORINGS...........................................463.1 General.........................................................................................463.2 Depth of Bores..............................................................................463.3 Method of Boring...........................................................................463.4 Sampling, Testing and Boring Logs.................................................47

3.4.1 Sampling and Testing......................................................................................473.4.2 Testing frequencies.........................................................................................473.4.3 Boring Logs.....................................................................................................47


Volume 3 – Technical Specification Borings for Pile Bearing Capacity- 45 -

1. DESCRIPTION

This specification describes the requirements and procedures for Soil

Investigation in locations as may be required by the Engineer or required

by the Contractor for information to confirm pile driving conditions or

foundation bearing capacity.

2. REFERENCE STANDARDS

The following Standards in their latest edition shall be particularly applied

to the works covered by this specification.

22TCN-259-2000

Specification for Geological Exploratory Drilling

ASTM D422 Particle-Size Analysis of SoilsASTM D854-06 Specific Gravity of Soil Solids by Water PycnometerASTM D1586 Penetration Test and Split-Barrel Sampling of Soils

ASTM D2113-06 Standard Practice for Rock Core Drilling and Sampling of Rock for Site Investigation

ASTM D2166 Unconfined Compressive Strength of Cohesive Soil

ASTM D2216 Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

ASTM D2487-06 Classification of Soils for Engineering Purposes (Unified Soil Classification System)

ASTM D2974 Moisture, Ash, and Organic Matter of Peat and Other Organic SoilsASTM D4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils

3. SOIL INVESTIGATION BORINGS

3.1 General

As may be required by the Contractor, subject to the approval of the

Engineer, or as may be required by the Engineer, the Contractor shall

carry out drilling and sampling for soil investigations at the selected

locations to obtain necessary subsurface data, information and/or

samples for testing.

The methods and procedures for soil investigation shall be in accordance

with the Vietnamese, AASHTO or ASTM standards listed above as may be

appropriate.

3.2 Depth of Bores

Soil test drilling shall be taken to the depth as required by the Engineer or

as necessary to establish the required foundation information. In the case

of structural foundations the test drilling shall generally be sufficient to

prove continuity of the bearing stratum.

3.3 Method of Boring

(a) The Contractor shall use rotary drilling as required in the standards

referred to above unless otherwise approved by the Engineer.


(b) Rock cores if required shall be continuously core drilled.

3.4 Sampling, Testing and Boring Logs

3.4.1 Sampling and Testing

(a) Sampling shall be performed in accordance with the requirements of

22TCN-259-2000.

(b) Standard penetration tests shall be taken at two (2)-meter intervals

or at each change of strata whichever is lesser for all borings unless

otherwise directed by the Engineer.

(c) The static ground water level shall be recorded for each hole.

(d) Rock cores shall be taken when and where required by the Engineer.

The full core shall be recovered and stored in core boxes for

inspection by the Engineer.

(e) Split-spoon (undisturbed samples) shall be taken when and where

required by the Engineer. These sample cylinders shall be sealed for

transport of the sample from site to the testing laboratory.

3.4.2 Boring Logs

(a) The Contractor shall supply drilling logs to the Engineer on the

working day following completion of each boring.

(b) The drilling logs shall be compiled by an experienced soils

technician or engineer.

(c) All boring logs shall contain, but not be limited to, the following

information and data:

① Structure name② Bore position and code number ③ Reduced level of top of the bore④ Date and time of boring⑤ Diameter of bore⑥ Type of plant used⑦ Depth to which bore was cased⑧ Depth to base of each stratum from the surface⑨ Description of strata⑩ Depth and results of standard penetration testing tests (if

required)⑪ Depth of any split-spoon sampling (if required)⑫ Static water level⑬ Remarks

(d) All descriptions and classifications of soils shall be in accordance

with ASTM D2487 Classification of Soils for Engineering Purpose

(Unified Soil Classification System)

(e) The Engineer may require additional testing to that described above

for any location should he find that the information obtained by the

Contractor is not adequate to confirm the soil parameters used in

the design.




(a) Soil investigation drilling shall be measured for payment by the

drilled depth of bore holes in metres regardless of the nature of

encountered materials.

(b) Where split-spoon samples are taken measurement shall be for the

number of samples taken.


Payment shall be made in accordance with the applicable unit prices of

the pay items of the Bill of Quantities listed below.

Payment shall be full compensation for all mobilization and

demobilization of drilling personal and equipment, drilling, casing (if

necessary), sample preparation, particle size distribution testing,

Atterberg Limits, standard penetration tests, other tests as required by

the Engineer, recording and presenting the results and storage of

samples until their disposal is approved by the Engineer.


07250-01 Soil Investigation Borings meter

07250-02 Penetration Test and Split-Barrel Sampling of Soils No.

Note.Where provision has been made in the Bills of Quantities for work included in this specification to be paid for against a Provisional Sum, payment shall be determined in accordance with the appropriate requirements of the Conditions of Contract.


SECTION 07300 - CAST-IN-SITU PILE

TABLE OF CONTENTS

1. DESCRIPTION....................................................................50

2. MATERIAL REQUIREMENTS.................................................502.1 Reference Standards.....................................................................502.2 Materials for Piling........................................................................50

2.2.1 Concrete.........................................................................................................502.2.2 Reinforcing Steel.............................................................................................502.2.3 Temporary Casings..........................................................................................502.2.4 Permanent Casings.........................................................................................512.2.5 Bentonite and Bentonite Slurry (Drilling Fluid)................................................512.2.6 Submittals.......................................................................................................51

3. CONSTRUCTION REQUIREMENTS........................................523.1 Boring...........................................................................................52

3.1.1 Boring Near Recently Cast Piles......................................................................523.1.2 Stability of Pile Excavation using Drilling Fluid................................................533.1.3 Spillage and Disposal......................................................................................533.1.4 Pumping from Bored Holes..............................................................................533.1.5 Cleanliness of Pile Bases.................................................................................533.1.6 Inspection.......................................................................................................53

3.2 Final Pile Toe Level........................................................................533.3 Reinforcement..............................................................................543.4 Concreting....................................................................................543.5 Extraction of Casing......................................................................56

3.5.1 Workability of Concrete...................................................................................563.5.2 Concrete level.................................................................................................563.5.3 Water Level.....................................................................................................56

3.6 Quality Control of Piling.................................................................563.6.1 General...........................................................................................................563.6.2 Testing of Materials for Drilling Fluid...............................................................563.6.3 Piling...............................................................................................................573.6.4 Integrity Testing of Piles..................................................................................583.6.5 Sonic Testing...................................................................................................593.6.6 Core Testing....................................................................................................59

3.7 Positional Tolerance......................................................................613.8 Reporting......................................................................................61

3.8.1 Daily Piling Records.........................................................................................613.8 Testing frequencies.......................................................................61


Volume 3 – Technical Specification Cast- in-situ pile- 49 -

1. DESCRIPTION

The work under this Specification Section consists of the construction of

Cast-in-Situ piles using the reverse circulation drilling method, crab type

hammers, and steel casing or any other earth drill method approved by the

Engineer, in accordance with this specification and in conformity with the

drawings or as may be required by the Engineer.

The work to be performed as specified in this Specification Section shall be

carried out after any required sub-soil investigations have been completed

by the Contractor in accordance with this specification, the drawings, or as

may be required by the Engineer.





ASTM A36 Carbon Structural Steel

OCMA DFCP4 Drilling Fluid Materials Bentonite Oil Companies Materials Association (OCMA)

API S13A Specification for Oil Well Drilling Fluid Materials (APIS: American Petroleum Institute Standard)

TCVN 326-04 or 22TCN 257-2000

Construction and Measurement of Cast-in-Situ Piles

2.2 Materials for Piling

2.2.1 Concrete

(a) Cast-in-Situ piles shall be constructed in accordance with the details

shown on the drawings using the class of concrete noted on the

drawings and in accordance with Specification - Concrete and

Concrete Structures

(b) Concrete shall be mixed and placed in accordance with the applicable

provisions of Specification - Concrete and Concrete Structures

2.2.2 Reinforcing Steel

Reinforcement shall comply with the provisions of Specification -

Reinforcing Steel 2.2.3 Temporary Casings

(a) Temporary casings shall be used to maintain the stability of pile

excavation, which might otherwise collapse.

(b) Temporary casings shall be free from significant distortion. They shall

have a uniform cross-section throughout each continuous length.

During concreting they shall be free from internal projections and

encrusted concrete which might prevent the proper formation of piles.


2.2.4 Permanent Casings

(a) Permanent casings shall be used as indicated on the drawings or

where required by the Engineer and shall conform to ASTM A36 or

equivalent.

(b) If the permanent casing is used in the boring operation or if the

handling and transportation require a greater thickness to avoid

deformation or buckling, the thickness shall be increased by the

Contractor at his own expense.

(c) Steel casings shall be furnished in appropriate lengths approved by

the Engineer.

(d) The casings shall be handled and stored in a manner that prevents

buckling and other deformation and the accumulation of dirt, oil and

paint. When placed in the work they shall be free from dirt, oil,

grease, paint, millscale and loose or thick rust.

2.2.5 Bentonite and Bentonite Slurry (Drilling Fluid)

(1) Supply

(a) Immediately prior to mixing Bentonite shall be in accordance with

Specification DFCP4 of the Oil Companies Materials Association

(Drilling Fluid Materials Bentonite), or the American Petroleum

Institute Standard 13A.

(2) Mixing

(a) Bentonite shall be mixed thoroughly with clean fresh water to make

a suspension which will maintain the stability of the pile excavation

for the period necessary to place concrete and complete

construction.

(b) Where chemically contaminated groundwater occurs, special

precautions shall be taken to modify the bentonite in all respects for

the construction of piles.

2.2.6 Submittals

(a) Prior to commencement of the Works and to complement the

investigation performed in accordance with Specification - Boring for

Pile Bearing Capacity, the Contractor shall submit to the Engineer for

his approval, a complete schedule for investigation of the site and

underground conditions in order to confirm the presence or absence

of obstructions (e.g. existing piles, sheet piles, remaining structures

or structural elements, cables, etc.).

(b) The Contractor shall submit to the Engineer for his approval, a

method statement detailing the proposed materials and methods of

construction of bored Cast-in-Situ piles using bentonite slurry or other

suitable materials. The method statement shall include but not be


limited to the details.

* Details of construction plant.

* Method and sequence of pile installation, including methods of avoiding damage to adjacent piles, utilities and structures, and method to clear the base of bored piles.

* Methods of controlling groundwater.

* Anticipated ground vibration, ground movement and groundwater drawdown and methods of instrumentation and monitoring.

* Methods of Quality control, sampling, testing, mixing, storing, recalculation, removal of silt and sand, prevention of spillage and disposal from the site.

* Proposals for the location and number of Test Piles

* Arrangements for pile testing including vertical loading and pile integrity testing program and method.

* Methods of concreting with methods of placing concrete by tremie.

* Particulars of the proposed materials and methods of construction using bentonite slurry or other agent.

* A certificate from the manufacturer of the bentonite powder showing the type, the manufacturer’s name, the date and place of manufacture and including details of the apparent viscosity range in centipoises and get strength range in N/mm2 for solids in water.

* Characteristics of the bentonite slurry in a freshly mixed condition and in the excavation immediately before concreting.

* Head of bentonite slurry, including calculations.

* The number and location of piles to be Load Tested shall be reviewed by and subject to the approval of the Engineer based on the Boring survey results by the Contractor.


3.1 Boring

3.1.1 Boring Near Recently Cast Piles

(a) Piles shall not be bored so close to piles which have recently been

cast and which contain workable or unset concrete such that a flow of

concrete could be induced from or damage caused to any of the piles.

(b) Where the Contractor intends to bore a new pile located close to a

recently bored pile Vietnamese Standard TCVN 326-04 or 22TCN-257-

2000 Construction and Measurement of Cast-in-Situ Piles shall be

applied and, unless otherwise instructed by the Engineer, the work

for boring the new pile shall depend on the confirmation that the

compressive strength of the recently bored pile has reached 70% of

its design strength.


3.1.2 Stability of Pile Excavation using Drilling Fluid

(a) Where the use of drilling fluid is approved for maintaining the stability

of a bore, the level of the fluid in the excavation shall be maintained

so that the fluid pressure always exceeds the pressures exerted by

the soils and external groundwater or at not less than 1m above the

level of the external groundwater. An adequate temporary casing

may be required in conjunction with the method to ensure stability of

the strata near ground level until concrete has been placed.

(b) In the event of a rapid loss of bentonite suspension from the pile

excavation, the excavation shall be backfilled without delay and the

instructions of the Engineer shall be obtained before excavation at

that location is resumed.

3.1.3 Spillage and Disposal

All reasonable steps shall be taken to prevent spillage of bentonite

suspension at the site and in areas outside the immediate vicinity of bore.

Disposal of discarded bentonite shall be in accordance with the

Contractor’s approved environmental management plan. 3.1.4 Pumping from Bored Holes

Pumping from a bored hole will not be permitted unless a casing has been

placed into a stable stratum which prevents the flow of a significant

quantity of water from other strata into the bore, or unless it can be shown

that pumping will not have a detrimental effect on the surrounding soil or

adjacent property. 3.1.5 Cleanliness of Pile Bases

On completion of boring, loose, disturbed or remolded soil shall be

removed from the base of the pile, using appropriate and approved

methods, which may include airlifting, and which shall be designed to clean

while at the same time minimizing ground disturbance below the pile base. 3.1.6 Inspection

(a) For a boring without casing, the diameter of the boring hole for a

representative number of piles will be measured by calipers prior to

the placing of concrete into it. The Contractor’s Quality Control

personnel shall do the measurement using approved equipment.

(b) The Contractor shall provide an approved means by which inspection

of the verticality of bored piles and reinforcement cages can be

performed.

3.2 Final Pile Toe Level

(a) Where required as indicated on the drawings and prior to the

commencement of pile boring at each pile cap or structure, proposed

founding levels shall be established from site investigation boreholes


(prebores) located at or near pile positions. Boreholes shall be in

accordance with requirements and procedures of Specification - Soil

Investigation Borings and/or as required by the Engineer. Where so

required, prebore results shall be submitted to the Engineer, at least

one month in advance of the piling work, to confirm the design of the

piles.

(b) During pile boring, the Contractor shall produce a boring log indicating

approximate depths and types of the various earth layers found in the

bore. Based on the existing conditions of boring, the Engineer might

require the Contractor to provide disturbed samples for visual

analysis.

(c) The Contractor shall immediately notify the Engineer if, during the

installation of piles, the ground conditions are different from those

indicated on the drawings or observed in the prebore.

(d) The Engineer will confirm the final pile toe level after his inspection of

the earth layers penetrated by the pile.

(e) The Contractor shall prepare for carrying out sampling and tests to

check bottom soils and excavation geometry.

3.3 Reinforcement

(a) Steel reinforcement shall be fabricated in accordance with the sizes

and dimensions shown on the drawings, and shall be placed, centered

and braced in the pile hole to the approval of the Engineer.

(b) Particular care shall be taken in locating projecting "column dowel

bars", with a tolerance not exceeding 10 mm in any direction, and

pouring will not be permitted until the Engineer is satisfied that

adequate provisions have been made.

(c) Adequate "shoes" or spacers shall be firmly anchored to the

reinforcement to ensure that the reinforcement is kept centered in the

concrete.

(d) The Contractor shall include in his construction method for pile

construction submitted to the Engineer for his approval, the working

drawings and details related to the placing of the reinforcement cage,

splicing procedures, measures and equipment to prevent damage to

the bored hole and maintain the stability of the bore while the cage is

being placed and procedures to control the verticality and consistency

of the cage during placing operations.

3.4 Concreting

(a) Immediately after the activities for boring excavation, placement of

reinforcement cage and cleaning of the borehole have been completed,

the Contractor shall request the Engineer’s approval for the


commencement of concreting.

(b) Before placing concrete, measures shall be taken to ensure that there

is no accumulation of silt or other material at the base of the bore.

(c) Once the Engineer’s approval for the commencement of concreting has

been obtained, concreting shall start without delay and continue

without interruption. In a boring which contains water or drilling fluid

the concrete shall be placed by tremie.

(d) Concrete shall be a rich coherent mix of high workability having a

measured slump of 130 - 170 mm.

(e) Concrete shall be placed in such a manner that segregation does not

occur.

(f) During and after concreting care shall be taken to avoid damage to the

concrete due to pumping and dewatering operations.

(g) The hopper and pipe of the tremie shall be clean and watertight

throughout. The pipe shall extend to the base of the pile and a sliding

plug or barrier shall be placed in the pipe to prevent direct contact

between the first charge of concrete and the water. The pipe shall at

all times penetrate the concrete that has previously been placed and

shall not be withdrawn from the concrete until completion of

concreting. At all times a sufficient quantity of concrete shall be

maintained within the pipe to ensure that the concrete pressure

exceeds the water pressure. The tremie pipe shall be kept at least 2.0m

but never more than 5.0m. under the concrete level. The internal

diameter of the tremie pipe shall not be less than 150mm for concrete

made with 20mm aggregate and not less than 200 mm for concrete

made with 40mm aggregate. It shall be so designed that external

projections are minimized, allowing the tremie to pass through

reinforcing cages without causing damage. The internal face of the

pipe of the tremie shall be free from projections.

(h) Measurement of the level of concrete surface shall be taken

immediately before and after any vertical movement of the tremie

pipe.

(i) The Contractor shall ensure that heavily contaminated bentonite

suspension, which could impair the free flow of concrete from the pipe

of the tremie, has not accumulated in the bottom of the hole.

(j) A sample of the bentonite suspension shall be taken from the base of

the bore using an approved sampling device. If the specific gravity of

the suspension exceeds 1.25 the placing of concrete shall not proceed.

In this event, the Contractor shall modify or replace the bentonite as

approved to meet the specification.


3.5 Extraction of Casing

3.5.1 Workability of Concrete

Temporary casings shall be extracted while the concrete within them

remains sufficiently workable to ensure that the concrete is not lifted.

Should a semi-dry mix be used the means of ensuring that the semi-dry

concrete does not lift during extraction of the casing shall be submitted to

the Engineer for his approval. 3.5.2 Concrete level

(a) When the casing is being extracted, a sufficient quantity of concrete

shall be maintained within it to ensure that pressure from external

water or soil is exceeded and that the pile is neither reduced in

section nor contaminated.

(b) Concrete shall be placed continuously as the casing is extracted until

the desired concrete level is obtained. The pile shall be cast to an

over-height approved by the Engineer to allow for cutting back to the

required level to ensure sound, uncontaminated concrete in the head

of the pile. No concrete shall be placed in the bore once the bottom of

the casing has been lifted above the top of the concrete.

(c) Adequate precautions shall be taken in all cases where excess

hydraulic heads could occur as the casing is withdrawn due to the

displacement of water by the concrete as it flows into its final position

against the walls of the shaft.

(d) The use of vibrating casing extractors shall be subject to the approval

of the Engineer.

3.5.3 Water Level

The Contractor shall submit to the Engineer for his approval suitable

proposals for dealing with groundwater levels higher than the required pile

head casting level shown on the drawings prior to placing concrete. The

pile head shall not be left below the groundwater level unless approved

precautions are taken.

3.6 Quality Control of Piling

3.6.1 General

The Contractor shall comply with his approved Quality Assurance Plan.3.6.2 Testing of Materials for Drilling Fluid

(a) Prior to the commencement of the work, the Contractor shall propose

the method and procedure of sampling and the frequency of testing

drilling fluid based on the referenced standards for drilling fluids. The

frequency may subsequently be varied depending on the consistency

of the results obtained.

(b) Control tests shall be carried out on the bentonite suspension using


suitable apparatus. The density of freshly mixed bentonite suspension

shall be measured daily as a check on the quality of the suspension

being formed. The measuring device shall be calibrated to read to

within 0.01g/ml. Bentonite supplied to the pile bore shall be tested to

determine density, viscosity, shear strength and pH values. For

average boil conditions the results shall generally be within the ranges

stated in the table in this specification clause. The tests shall be

continued until a consistent working pattern has been established,

account being taken of the mixing process, any blending of freshly

mixed bentonite suspension and previously used bentonite suspension

and any process which may be used to remove impurities from

previously used bentonite suspension. When the results show

consistent behavior, the tests for shear strength and pH value may be

discontinued, and tests to determine density and viscosity shall be

carried out as approved by the Engineer.

(c) The Contractor shall submit to the Engineer for his approval the

method proposed for the sampling and checking of contaminated

bentonite and for the cleaning of the base of the bore. In the event of

a change in the established working pattern, tests for shear strength

and pH value shall be reintroduced for a period if required.

Property to be measured

Range of results at 20o C Test method

Density Less than 1.10g/ml Mud density balance

Viscosity 30-90s or Less than 20 cP

Marsh cone method Fann viscometer *

Shear strength(10 minute gel strength)

1.4-10 N/m2 or 4-40 N/m2

ShearometerFann viscometer

PH 9.5-12 pH indicator strips or electrical pH meter

* Where the Fann viscometer is specified, the fluid sample should be

screened by a # 52 sieve (300/um) prior to testing. 3.6.3 Piling

The Contractor shall designate a competent and experienced technician to

be in charge of the piling operations at the site and to be responsible for

the quality control of the work including, but not limited to, the following:

(a) Ensuring proper storage and handling of all the materials for pile

fabrication.

(b) Ensuring proper maintenance and cleanliness of plant (including that

for bentonite preparation), cranes, trucks, and other equipment.

(c) Work in close coordination with Contractor’s staff responsible for

quality control under other specification sections.


(d) Continuous monitoring of the quality of bentonite and other materials

used for piling.

(e) Proper preparation of the work before, during and after concrete

pouring.

(f) Proper preparation and performance for piles (including the Test Piles

if required according to the drawings or by the Engineer) as stated in

this specification.

(g) Proper preparation and timely submittal of the data and reports

specified in clause 3.8 of this specification.

(h) Preparation of working drawings, details, equipment related to the

measures to prevent, or to correct, defective piles or to be carried out

in the event that a borehole collapses during or before concreting

work.

3.6.4 Integrity Testing of Piles

The number of piles to be tested to determine their integrity shall be as

stated on the drawings. Testing shall be by Sonic Test and Core Test as


For the purpose of testing the pile integrity by Sonic Test and core drilling,

all Cast-in-Situ piles shall be constructed with steel pipes cast in place as

detailed on the drawings.

All the following requirements shall be satisfied:

(a) The Contractor shall submit a complete plan of testing describing the

methodology and equipment to be used for testing.

(b) The length of steel tubing shall extend to the limits indicated on the

drawings.

(c) All tubing shall extend to at least 30 mm above the top of any

permanent or temporary pile casing.

(d) The bottom of the tube shall be permanently sealed

(e) The top of the tube shall be provided with a screw type plug, to

prevent the intrusion of foreign materials into the tube.

(f) Tubes shall be placed continuously straight from the bottom to the

top so as to allow later introduction of Sonic Coring and core drilling

apparatus.

(g) During placement, the tubes shall be kept free of all foreign

materials.

(h) The Contractor shall be responsible for any corrective work

necessary if testing and/or coring cannot be accomplished because

of improper placement and/or the presence of obstructions in the

tubing.


(i) When required by the Engineer, the Contractor shall fill all tubes with

an expansive grout, acceptable to the Engineer, which is capable of

displacing any water in the tubes. The grout shall be continuously

injected into the tubes from the bottom of the tube to the top.

3.6.5 Sonic Testing

(a) Test shall not be carried out until the pile concrete has gained its 28

days characteristic strength.

(b) Sonic and Impulse Testing shall be carried out by approved specialist

firms, from whom a full method statement shall be obtained and

approved by the Engineer prior to commencement of testing. One

hundred percent (100%) of piles shall be tested .

(c) The interpretation of the results shall be carried out by competent

persons and an indication of the result of all testing shall be passed to

the Engineer immediately on completion of all tests. A full written

report shall be provided directly to the Engineer within 10 days after

the completion of the test.

3.6.6 Static load test on ‘’ working piles’’

The contractor shall submit his proposal for conducting static load tests to

the Engineer for this approval.

Unless otherwise directed by the Engineer the test load shall be applied in

the following sequence:

(a) Apply an initial load of 5% required pile – working load.

(b) Remove the initial load and set recording instruments to zero.

(c) Increase load to the required pile-working load, as shown on the

Drawings, by four equal increments.

(d) Deflection shall be read just after each load increment or

decrement is applied and at 15 minutes intervals thereafter. The

next increment or decrement shall not be applied until the rate of

settlement has decreased to 0.05 cm/hour and the load has been

sustained for at least one hour.

(e) The pile-working load shall be maintained for at least 12 hours.

(f) Reduce load to zero by similar equal decrements.

(g) Increase load to 1.5 times the required pile-working load by six

equal increments and maintain at this load for at least 24 hours.

(h) Reduce load to zero by similar equal decrements.


(i) When directed by the Engineer, a third test cycle shall be carried

out as follows:

Increase load to 2.0 times the required pile working loads by eight equal increments and maintain at this load for 12 hours or as directed by the Engineer.

(j) For acceptance, the total pile top displacement under 1.5 times pile

working load and after its subsequent removal shall not exceed the

following values:

Loaded Unloaded

For bored cast-in-place piles1.5%

0.75%

of the pile diameter

(k) Instrumentation shall be installed as directed by the Engineer and

readings taken at each increment, all in accordance with the

manufacturer’s recommended procedures.

Test Results on Pilot and Working Piles

(a) The Contractors shall submit within 48 hours of the completion of

the pile test to the Engineer for each pile tested a detailed record

of testing and, in addition, graphs showing:

Load and pile top displacement plotted above and below a

common base line of time for static load tests.

Pile top displacement plotted vertically against a base line of

load for static load tests.

Top pile displacement Vs mobilized static resistance plot as

assessed from dynamic load test using CAPWAP – Method.

(b) A full comprehensive written report shall be submitted to the

Engineer within 10 working days for approval.

(c) After the completion of loading tests, all equipment and load used

shall be removed from the site.

(d) If the results of the load tests on “Working piles” shall be

considered as not having complied with the criteria specified or

required a further pile shall be tested. If this second pile test also

does not comply with specifications or requirements, the Engineer

shall order changes to the pile group as he considers necessary.


New pile or piles shall be installed to replace the defective pile in a

position or positions as instructed by the Engineer.

3.6.7 Core Testing

(a) As required by the Engineer, core drilling shall be provided for

completed piles to at least 600 mm below the bottom of the pile. The

cores obtained shall be placed in core boxes and the drill-hole

identification shall be clearly marked on each respective core and

box. Three (03) samples shall be taken from 2% of piles.

(b) Upon satisfactory completion of tests, all voids formed by core drills

shall be pressure grouted with non-shrink grout in accordance with

this specification.

3.7 Positional Tolerance

The positional tolerances for cast in-situ piles shall be as follows:-

a) The centre of the completed pile at the cut off level shall not deviate more than 80mm from the theoretically correct position shown on the Drawings.

b) The inclination of the pile shall not deviate more than 1:100 from the required vertical alignment.

c) After completion of all piling work and prior to casting the pile top into the pile cap or foundation, the top of the reinforcement cage shall be no more than 150 mm above and no more than 75 mm below the correct position and the top of the concrete shall be within 25 mm of the correct elevation.

d) The bottom of the shaft excavation shall be normal to the axis of the pile within 60 mm per meter of pile diameter

e) Where a casing is used, its outside diameter shall not be less than the shaft diameter shown on the Drawings. The diameter of cast in-situ piles shall be at least 97% of the specified diameter

3.8 Reporting

3.8.1 Daily Piling Records

The Contractor shall furnish the Engineer with a detailed daily record of

soils encountered during excavation and construction of the piles.

The Contractor shall keep records of the installation of each pile and shall

submit two signed copies of these records to the Engineer not later than

24 hours after the pile was installed. The signed records shall be as

indicated in the following table.

Table 1 Records of pile borings:

(a) Contract Name and Date

(b) Pile reference number (location)


(c) Pile type

(d) Nominal cross-sectional dimensions or diameter

(e) Nominal diameter of under-ream

(f) Length of performed pile

(g) Standing groundwater level

(h) Date and time of boring

(i) Date of concreting

(j) Ground level at commencement

(k) Working level

(l) Depth from working level to pile toe

(m) Toe level

(n) Depth from working level to pile head level

(o) Length of temporary casing

(p) Length of permanent casing

(q) Vertical of borehole

(r) Set of pile or pile tube in mm per 10 blows or number of blows per 25 mm of penetration

(s) Soil samples taken and in-place tests carried out

(t) Length and details of reinforcement

(u) Concrete mix

(v) Volume of concrete supplied to pile where this can be measured in practice and corresponding levels of concrete and casing

(w) All information regarding obstructions, delays and other interruptions in the sequence of work

(x) Strength of corresponding concrete cylinders

(y) If grouting done, mix and quantity of grout used.


Testing frequencies shall be accordance with Vietnamese Standard: TCVN 326-04 or 22TCN 257-2000 or other international standard subject equivalence being demonstrated by the Contractor and the satisfaction of the Engineer of the Vietnamese standard shall apply:

Item Test Description

Test Frequency Remark

1 TCXDVN 326-04 or 22TCN 257-2000 : Bored pile - Code of Construction and acceptance standard

a


Bentonite liquid : Article 11.2 Table 1 Cement concrete for bore piles : Article 11.5


b During construction period:

Boreholes checking : Article 11.3Table 2; Table 3

Reinforcemnet grid tolerance : Article 11.4 Table 4 Cement concrete for bore piles : Article 11.5 Table 5


Loading testing for bore plies : Article 11.6 (static load, & PDA)



The Cast-in-Situ piles shall be measured for payment by linear meters of

piles cast and left in place in the completed and accepted work.

Measurement shall be made from the bottom of the pile to the bottom of

the foundation (the lower plane as defined for structural excavation)

indicated on the Drawings. Portions of piles cast deeper than required

through over-excavation procedures shall not be measured for payment.

In case that the presence of an obstruction affects the construction works,

the Contractor shall immediately submit to the Engineer, for approval, his

proposed countermeasures and detailed schedule to avoid delays in the

Project. In the event that the requirements for the before mentioned

investigation on the existing site conditions are not duly complied by the

Contractor, no time extension and neither additional payment shall be

allowed for the countermeasures, and the materials and incomplete works

performed by the Contractor before encountering the obstruction shall not

be subject to any payment.


The accepted quantities, measured as provided above, shall be paid at the

contract price per unit of measurement for the pay items of the Bill of

Quantities listed below.

Payment shall be full compensation for the work prescribed in this Section

including, but not necessarily limited to, the following:

(1) Cast-in-Situ Piles

All of the cost mentioned bellow is included.

① Placement of cage for reinforcement, integrity testing tubing, protection of existing piles and structures, hauling, handling, jetting, jointing, cutting and all other incidental works related thereto

② all expenses involved in providing pumps, cofferdams, braced sheet piling or any other methods approved by the Engineer;

③ all expenses resulting from the Contractor's


observance of all rules and regulations of relevant competent authorities regarding the interference or maintenance of flow in the canals, water courses, channels or pipes related to the Project

④ provisions for and driving and removal of sheet piles including providing certification by an Independent Engineer;

⑤ provisions for placement and removal of temporary Jetty/Guide frames;

⑥ provisions for underwater works;

⑦ provisions for underwater concrete;

⑧ previsions for pumps and dewatering by submersible pumps;

⑨ provisions for all necessary barges; and

⑩ provisions for all necessary tugboats and auxiliary river craft.

⑪ And for furnishing all labor, materials, tests, tools, equipment and any incidentals to complete the work as shown on the Drawings and as required by these Specifications, and/or as directed by the Engineer.

(2) Permanent Casing

Payment shall include all expenses for furnishing materials, equipment

and instruments, technicians and experts for completion of the

installation of permanent casing as described in clause 2.2.4.

Temporary casing shall be considered incidental to the prices in the Bill

of Quantities and shall not be paid for separately.

(3) Pile Core Tests

Payment shall include all expenses for furnishing all materials,

equipment and instruments, technicians and experts for completion of

the pile core tests.


07300 – 01

07300 - 02

Cast-in-Situ Pile 1,200 mm diameter (in land)Cast-in-Situ Pile 1,200 mm diameter (on water)

lmlm

07300 – 03

Permanent Casing (1,200 mm) lm

07300 – 04

Pile Core Test each

07300 – 05

Static pile Test Nos

07300 – 06

Humus testing at top pile Nos

07300 – 07

Ultrasonic Test section


North – South Expressway Construction Project Tender documents(Ho Chi Minh – Dau Giay Section) Contract Package 1A

Volume 3 – Technical Specification Pile DynamicTesting- 65 -


SECTION 07350 – PILE DYNAMIC TESTING

1. DESCRIPTION....................................................................67

2. EQUIPMENT AND MATERIAL REQUIREMENTS.......................67

3. SPECIALIST.......................................................................68

4. REPORTING RESULTS.........................................................68

5. METHOD OF PAYMENT.......................................................68

6. BASIS OF PAYMENT...........................................................69



1. DESCRIPTION

The work shall consist of furnishing all materials, equipment, and labour necessary for conducting high-strain dynamic tests on drilled and cast-in-place piles. 2% of all completed piles shall be selected for testing as approved by the Engineer. The Contractor shall appoint an Independent Specialist to conduct all testing and shall supply materials, equipment and labour as specified, for work prior to, during, and after the tests all to the approval of the Engineer. Testing procedures shall conform to ASTM D4945-89 unless noted otherwise. The shaft used for the test will be instrumented and tested by the Independent Specialist, as approved by the Engineer, meeting requirements outlined in the ASTM D4945-89 specification as well as those outlined below.

2. EQUIPMENT AND MATERIAL REQUIREMENTS

The Contractor shall supply all labour, materials and equipment required to prepare and dynamically load the test pile, and return the pile to a condition suitable for use in the finished structure. The Contractor’s equipment and methods shall include but not be limited to:

The extension of the pile top if a permanent casing has not been used to construct the pile. The extension shall be formed of a thin walled casing or equivalent and shall be at least equal to two and a half (2 ½) pile diameters such that the extended pile head can be readily accessed by the testing engineer at the time of the test. If the pile top is below grade, the Contractor shall remove the surrounding soil to expose the pile top in a safe working environment.

A flat, level, and sound concrete top to the pile perpendicular to the vertical axis of the pile. The top of the concrete should be level with or above the casing. Prior to the test, four “windows” approximately 150mm. by 150mm. shall be provided in each quadrant of the casing.

A drop weight in the range of one and half to two percent (1.5% to 2%) of the anticipated pile capacity to be approved by the Engineer.

A guide allowing variable drop heights typically between 2 to 3m to be approved by the Engineer.

A shaft top cushion consisting of new sheets of plywood with total thickness between 50mm. and 150mm. to be approved by the Engineer.

A steel striker plate at least 50mm. thick and an area between 70% and 90% of the area of the pile top, but not less than the area of the impacting surface of the drop weight, shall be placed on top of the plywood cushion.

Where reinforcement protrudes above the top of the pile the Contractor may:

Incorporate the reinforcement into the test area in the manner of a pile extension. Upon successful completion of the



dynamic test the extension can be removed to make the pile suitable for use in the structure.

Ensure at least 20% of the pile cross sectional area is available for sufficient length such that the ram impact will not interfere with the reinforcing bars. In such case steel striker plates and plywood cushions must be sized so that they cover as much as the impact area as possible.

One (1) k of 200 Volt AC Power.

Surveyor’s level, laser light or equivalent for measurement of pile set under each impact.

3. SPECIALIST

Testing is to be performed by an accredited Specialist from a firm with a minimum of four (4) year experience in dynamic load testing. The actual test shall be conducted and/or supervised by a practicing Geotechnical Engineer with at least five (5) years of dynamic testing experience. The firm selected by the Contractor must be approved by the Engineer.

The Specialist must supply the following testing instrumentation in addition to instrumentation outlined in ASTM specification D4945-89 Section 5:

a) Pile Driving Analyzer (PDA)

b) Calibrated Strain Transducers

c) Calibrated Accelerometer

4. REPORTING RESULTS

The Specialist shall promptly submit a report of the testing results to the Engineer for approval. The field results from at least one (CAPWAP) analysis (case Pile Wave Analysis Program) shall be submitted. The CAPWAP analysis shall be performed by an experienced and qualified Engineer. The report shall also provide the following:

a) Wave Equation analysis results obtained prior to testing

b) CAPWAP analysis result.

c) For each impact the maximum measured force, maximum calculated tension force, transferred energy to the gage location, corresponding stresses, and the Case Method bearing capacity.

d) Assessment of the test result with respect to both pile capacity and integrity.

5. METHOD OF PAYMENT



The quantity to be paid for shall be the number of bored piles tested and accepted. Any item indicated and not otherwise described hereto shall be considered subsidiary to the work item and shall not be paid for separately.

6. BASIS OF PAYMENT

Payment shall be made for each test together with the relevant report accepted by the Engineer at the contract price shown below. The payment shall constitute full compensation for the cost of Pile Dynamic Testing, the cost of appointing an Independent Specialist, all instrumentation, testing and testing equipment, analysis and reporting, tools, labour and all other incidentals necessary to complete the work prescribed in this Item.

Payment will be made under:

Pay Item Number

Description Unit

07350 – 01 PDA tests Nos



SECTION 07400 - PRESTRESSED CONCRETE

TABLE OF CONTENTS

1. DESCRIPTION....................................................................71

2. MATERIAL REQUIREMENTS.................................................712.1 Reference Standards.....................................................................712.2 Material for Prestressed Concrete..................................................71

2.2.1 General Requirement......................................................................................712.2.2 Prestressing Steel............................................................................................712.2.3 Anchorages for post tensioning.......................................................................722.2.4 Ducts (Sheath)................................................................................................732.2.5 Grout for Ducts................................................................................................732.2.6 Concrete.........................................................................................................742.2.7 Submittals.......................................................................................................74

3. CONSTRUCTION REQUIREMENTS........................................753.1 General.........................................................................................753.2 Sampling and Testing....................................................................76

3.2.1 Grouting Trials.................................................................................................763.2.2 Site Flow Tests.................................................................................................773.2.3 Testing of Pre-cast Pre-stressed Members.......................................................77

3.3 Placing Steel.................................................................................773.4 Pretensioning Method...................................................................773.5 Post-tensioning Method.................................................................783.6 Grouting.......................................................................................79

3.6.1 Plant for Grouting............................................................................................793.6.2 Grouting of Ducts and Sheathing....................................................................79

3.7 Protection of Prestressing Anchorages...........................................803.8 Superstructure Construction..........................................................813.9 Curing...........................................................................................82

3.9.1 General...........................................................................................................823.9.2 Steam Curing..................................................................................................82

3.10 Handling, Transport and Storage....................................................833.11 Marking of Precast Prestressed Members.......................................833.12 Erection of Pre-cast Beams............................................................833.13 Tolerances for Pre-stressed Concrete Structures.............................843.14 Testing frequencies.......................................................................84


Volume 3 – Technical Specification Prestressed Concrete- 70 -


1. DESCRIPTION

(a) This work consists of the construction of pre-stressed concrete

structures and pre-stressed concrete portions of composite structures in

conformity with the design, lines, grades, and dimensions shown on the

drawings or as may be established by the Engineer in accordance with

this and other relevant specifications.

(b) The work shall include the supply and installation of any items

necessary for the particular pre-stressing system to be used, including

but not limited to ducts, anchorage assemblies and grout used for

pressure grouting ducts.

(c) It shall include the manufacture, transportation, and storage of beams,

slabs, and other structural members of pre-cast concrete pre-stressed

by either pre tensioning or post-tensioning methods. It shall also

include the installation of all pre-cast pre-stressed members.





AASHTO M235 Epoxy Resin Adhesives

22TCN 272-05 Specification standard for Bridge design

AASHTO LRFD Bridge Design Specifications, Deflection Criteria for Girders, Section 2.5.2.6.2.

ASTM A421-91 Un-coated Stress Relieved Steel Wire for Prestressed Concrete;

ASTM A416-99 Steel Strand, Un-coated Seven Wire Stress Relieved Strand for Prestressed Concrete.

2.2 Material for Prestressed Concrete

2.2.1 General Requirement

All materials to be furnished and used, but not covered in this specification,

shall conform to the requirements stipulated in other applicable

specifications. 2.2.2 Prestressing Steel

(a) High tensile strength steel wire shall be stress relieved and shall

conform to the requirements of ASTM A421-91 or equivalent for Un-

coated Stress Relieved Steel Wire for Pre-stressed Concrete

(b) High tensile steel strand with low-relaxation shall be weld free and

stress relieved after stranding and shall conform to the requirements

of ASTM A416-99 or equivalent Steel Strand, Un-coated Seven Wire

Stress Relieved Strand for Prestressed Concrete

(c) Testing of pre-stressing reinforcement shall be in accordance with the



requirements of the ASTM Specifications for the type of system

intended to be used or subject to approval by the Engineer.

Fpu – Specsified tensile strength of pretressing steel (Mpa)

Fpy – Yield strength of pretessing steel (Mpa)

2.2.3 Anchorages for post tensioning

(a) All anchorage assemblies shall be subject to the approval of the

Engineer.

(b) All post-tensioned pre-stressing steel shall be secured at the ends by

means of approved permanent type anchoring devices. The

Contractor shall submit information and details, including test

certifications for by the Engineer.

(c) End anchorage devices (stress and dead anchors) shall be designed



and manufactured for the types of tendons to be used. They shall

have a previous service record of performance and durability when

used on similar type work.

(d) All anchorage devices for post-tensioning shall be capable of holding

the pre-stressing steel at a load producing a stress of not less than 95

percent of the guaranteed minimum tensile strength of the pre-

stressing steel.

(e) Fixed anchorages for tendons in pre-cast beams shall be of steel

bearing plate type while all remaining anchorages shall be those

capable of adjustment by means of a threaded anchor head and ring

nut.

(f) It shall be the responsibility of the Contractor to confirm the required

bursting reinforcements in the local zone for the particular shape and

design of the anchorage devices proposed.

(g) All externally exposed steel parts shall be protected from corrosion.

All threaded parts and fittings shall be protected by greased

wrappings or plugs until used. Anchorages shall be kept free from

dirt, mortar, loose rust or other deleterious materials. Damaged

anchorage parts shall not be used.

2.2.4 Ducts (Sheath)

(a) Ducting for internal tendons shall be fully compatible with the

proposed pre-stressing system. The ducts shall be fabricated from

corrugated galvanized sheet steel or semi-rigid conduit.

(b) Minimum duct thickness shall be as follows:

* 26 gauge for duct diameter less than or equal to 67 mm

* 24 gauge for duct diameter greater than 67 mm

* 31 gauge for bar tendons

(c) Ducts shall have grouting connections at each end and shall have

vent/drains at all intermediate high and low points, subject to the

approval of the Engineer.

2.2.5 Grout for Ducts

Unless otherwise specified in other prevailing sections, or subject to

approval by the Engineer as a result of grouting trials, the grout shall:

(a) consist only of ordinary Portland cement, water and expansive

admixtures approved by the Engineer and used in accordance with

the manufacturer’s instructions;

(b) have a water to cement ratio as low as possible consistent with the

necessary workability, and under no circumstances shall the

water/cement ratio exceed 0.40;



(c) not contain admixtures containing chlorides, nitrates or similar

electrolytic conducting materials.

2.2.6 Concrete

(a) Concrete shall be of the class indicated on the drawings and shall

conform to the requirements of Specification - Concrete and Concrete

Structures and the requirements specified below unless otherwise

stated on the drawings or as may be required by the Engineer.

(b) The maximum size of aggregate for use in the manufacture of pre-

stressed concrete shall be 25 millimeters.

(c) The main properties of concrete such as compressive strength after

28 days, Modulus of Elasticity (Young Modulus), and other properties

that were used for the detailed design shall be confirmed by testing

of samples of the approved mix design. The Contractor shall perform

the tests in accordance with the appropriate standards, or as may be


2.2.7 Submittals

The Contractor shall prepare, check and submit detailed Contractor’s

Drawings and Schedules together with calculations to the Engineer for his

review and approval well before superstructure construction is

programmed to start. Details and design shall be checked by a properly

qualified engineer who shall confirm the adequacy and safety of the

proposed details by certifying and stamping the designs and drawings.

Expenses incurred in connection with this certification shall be borne by

the Contractor. Concrete shall not be cast prior to the Engineer’s approval

of these requirements.

The Contractor’s submittals shall include where required, but not limited

to, the following:

Geometry Control PlanDetailed procedures and methods for controlling the geometry at every stage of construction.

Temporary worksTemporary fixing/stabilizing method of the supports and closures during erection operationsTravelling forms, suspended false-work or scaffolding, girder erection gantriesForm-work and false-workDimensions and complete descriptions of all devices, joints, bearings, and anchorages not specified or detailed in the Specifications

Pre-stressingMethod and timing of the insertion of pre-stressing cables.Post-tensioning or Pre-tensioning hardware, jointing, jacking, grouting equipment, and men and materials of any kindVertical alignment and deflection control measures with calculations



of pre-camber by pre-stressing forces, loads, temperature range and effects of creep and shrinkage of concrete

GroutingStatement for grouting of ducts

Casting and curing Detailed Casting Manual describing all the activities in a step-by-step procedure Methods of controlling of deflection to ensure the accuracy of alignment of the completed superstructure

Erection of members Equipment for all machinery, devices, labor and material which are to be used for erectionMethods of tie-down and closure of superstructures during erection

Cross Beam Installation and pre-stressing methods of cross beam

Deck Slab Fabrication and Installation methods of Concrete Form Works

Installation methods of Cast in Situ Slab on the Concrete Form Works


3.1 General

(a) The Contractor shall assign an experienced technician, skilled in the

use of pre-stressing system, who shall supervise the work being

performed in compliance with these specifications and to the

satisfaction of the Engineer.

(b) The Contractor shall provide all equipment necessary for construction

and pre-stressing. The equipment shall be of a currently manufactured

model, and shall be in good working condition. A pre-stressing system

approved by the Engineer shall be used. If hydraulic jacks are used

they shall be equipped with accurate pressure gauges. The

combination of jack and gauge shall be calibrated and a graph or table

showing the calibration shall be provided to the Engineer. Should other

types of jacks be used, calibrated proving rings or other devices shall

be furnished so that the jacking forces may be accurately known.

(c) The requirements for concrete construction in Specification - Concrete

and Concrete Structures shall be complied with, except as may be

modified in this specification. Pre-stressed concrete shall be formed,

stressed, placed, cured, and protected at shops, manufacturing plants,

and locations where the fabrication of such members may be properly

inspected and controlled and approved by the Engineer.

(d) Vertical alignment and girder lengths shown on the drawings represent

dimensions at the time of final creep. Deflection criteria for girders

shall be in accordance with 22 TCN 272-05, longitudinal deflections

may be rectified by an appropriate approved method.



3.2 Sampling and Testing

3.2.1 Grouting Trials

(a) Where full scale trials are required they shall begin at least 21 days

before the planned commencement of the fixing of ducts for pre-

stressing in the permanent works unless otherwise specified in the

Contract.

(b) The trials shall incorporate all relevant details of ducts, vents, duct

supports, pre-stressing anchorages and couplers, pre-stressing

strands and grout inlets and outlets. Tendons shall be sufficiently

tensioned such that the strands within the duct take up a

representative alignment. All systems, methods and materials shall

be those proposed for the permanent works and shall have been

submitted to the Engineer as part of the Contractor’s detailed method

statement.

(c) Grouting shall be carried out in accordance with the requirements of

Sub-section 3.6.2 of this specification, and the following information

shall be recorded:

* fluidity of the grouting using a flow cone;* results of bleeding tests;* compressive strength of the grout;* temperature of the grout at the point of injection;* shade temperature;* grouting pressure close to the point of injection;* type of any admixture and results of control tests carried out by

the manufacturer to demonstrate its properties including those at appropriate hydration temperatures; and

* results of a visual inspection for detection of leakage.

(d) The arrangement of ducting, end plates injection and outlet

connections shown on the drawings shall be rigidly supported and an

actual or simulated bar tendon inserted but not stressed.

(e) After the grout strength has reached 17 Mpa, at least three samples,

each one of 1 meter long, shall be cut from the grouted duct at the

locations chosen by the Engineer. Each of the samples shall be

sectioned longitudinally by cutting with a high speed abrasive cutting

wheel, friction saw or similar. The sectioned samples shall be

delivered to the Engineer, who will assess the acceptability of the

grouting trials particularly in respect of the presence and location of

any voids in the samples.

(f) If the presence and location of voids are deemed to be unacceptable,

the Contractor shall amend the properties of the grout and/or

grouting procedures and carry out further trials, until an acceptable

result is obtained.

(g) Before commencing grouting trials the Contractor shall submit to the



Engineer details of the proposed ducting, method of support and

calculations substantiating that the ducting and any surrounding

supporting material will withstand the grouting pressure used during

the trials.

3.2.2 Site Flow Tests

Fluidity of the grout shall be tested on site at the time of mixing using the

Marsh Cone Test to ensure practicality of pumping and minimize the risk of

blockage during grouting operation. A target flow time of 10-15 seconds

shall be achieved. 3.2.3 Testing of Pre-cast Pre-stressed Members

Where required by the Engineer, one or more beams may be subjected to a

loading test. The Contractor shall obtain the prior approval of the Engineer

for the detailed arrangements for testing. The cost of tests and records

shall be included in the unit prices.

3.3 Placing Steel

All steel reinforcement shall be accurately placed in the position shown on

the drawings and rigidly held in place during placing and setting of the

concrete. Distance from the forms shall be maintained by stays, formwork

spacers, ties, hangers, or other approved support. Formwork spacers for

holding units from contact with the forms shall be of approved material,

shape and dimensions. Layers of reinforcement shall be separated by

suitable wire spacers. Wooden blocks shall not be used.

3.4 Pretensioning Method

(a) The pre-stressing elements shall be accurately held in position and

stressed by jacks. Stressing shall be applied to produce the stresses

required in the wires, strands or bars immediately after the anchorage

as shown on the drawings or as directed by the Engineer. Suitable

allowances shall be made for friction in the jacks and for slip and yield

in the grips or anchorages.

(b) Curing shall be by steam methods as described in clause 3.9.2, or

other methods subject to the approval of the Engineer.

(c) A record shall be kept of the jacking forces and the elongations

produced and the minimum age in hours of the concrete for each unit

until the time the tendons were released.

(d) No bond stress shall be transferred to the concrete, nor shall end

anchors be released, until the concrete has attainted a compressive

strength of not less than 85% of the specified 28-day strength as

shown by standard specimens cured in a similar fashion to the

element. The elements shall be cut or released in such an order that

eccentricity of pre-stress is minimized subject to the approval of the

Engineer.



3.5 Post-tensioning Method

(a) Post-tensioning shall be carried out in accordance with an approved

method and in the presence of the Engineer unless permission has

been obtained to the contrary.

(b) Immediately before tensioning, the Contractor shall prove that all

tendons are free to move in the ducts.

(c) Each anchorage device shall be set square to the line of action of the

corresponding post-tensioning tendon and shall be securely fixed in

position and gradient to prevent movement during the placing and

compaction of concrete.

(d) Except where dead-end anchorages are cast in the concrete, tendons

shall not be installed until just prior to stressing. Tendons shall be

pulled or pushed through the duct in such a manner as to avoid

damage to either the tendon or the duct.

(e) Unless approved otherwise, concrete shall not be stressed until 2 test

cylinders taken from it have attained the specified transfer strength.

The test cylinders shall be cured in conditions similar to the concrete to

which they relate in a manner approved by the Engineer.

(f) Where members consist of jointed elements, the strength of transfer of

the jointing material shall be at least equivalent to the specified

transfer strength of the members.

(g) The Contractor shall establish the datum point for measuring extension

and jack pressure to the satisfaction of the Engineer. Allowance shall

be made for the friction in the jack and anchorage for pull-in of the

tendon during anchorage.

(h) The tendons shall be stressed at a gradual and steady rate until the

required extension and tendon load are reached or are approved by the

Engineer. The sequence of stressing shall be as shown on the drawings

or directed by the Engineer.

(i) The force in the tendons shall be obtained from readings on a load cell

or pressure gauge incorporated in the equipment and the extension of

the tendons measured. The extension of the tendons under the

approved total forces shall be within the limits given below of the

agreed calculated extension.

Transverse Tendons for Segments:

±10% average for one tendon

± 7% for average of one segment

Longitudinal Tendons for Segments

± 5%

All other Tendons ± 5%



(j) If the measured extensions are not within the specified tolerance then

the Contractor shall submit to the Engineer his method of rectifying the

discrepancy.

(k) When the pre-stressing force has been applied to the satisfaction of the

Engineer, the tendons shall be anchored. The force exerted by the

tensioning apparatus shall then be decreased gradually and steadily so

as to avoid shock to the tendon or anchorage.

(l) Full records shall be kept of all tensioning operations including

measured extensions, pressure gauge or load cell readings and draw-in

at anchorage. Copies of records shall be supplied to the Engineer

within 24 hours of each tensioning operation.

(m) Unless otherwise agreed by the Engineer, tendons shall not be cut less

than 2 days after stressing.

3.6 Grouting

3.6.1 Plant for Grouting

(a) The grout mixer shall produce a grout of colloidal consistency. The

grout injector shall be capable of continuous operation with a sensibly

constant pressure up to 0.70-N/mm2 and shall include a system of

circulating or agitating the grout whilst actual grouting is not in

progress. All baffles to the pump shall be fitted with 1.18 mm sieve

strainers.

(b) The equipment shall be capable of maintaining pressure on

completely grouted ducts and shall be fitted with a nozzle that can be

locked off without loss of pressure in the duct.

(c) The pressure gauges shall be calibrated before they are first used in

the Works, and thereafter as required by the Engineer. All equipment

shall be thoroughly cleaned and washed with clean water at least

once every 3 hours during the grouting operations and at the end of

use for each day.

(d) During the grouting operation, the Contractor shall provide adequate

flushing-out plant to facilitate complete removal of the grout in the

event of a breakdown of the grouting equipment or other disruption

before the grouting operation has been completed.

3.6.2 Grouting of Ducts and Sheathing

(a) Grouting trials shall be undertaken when directed by the Engineer.

Prior to using the grout in any trial or in the works the Contractor shall

submit a detailed method statement for grouting procedures covering

proposed materials, sheathing, anchorage and vent alignment

equipment, and quality control to the Engineer for his approval.

(b) All ducts shall be thoroughly cleaned out by means of flushing with



water and/or water/compressed air.

(c) Grouting of ducts shall be carried out as soon as it is technically

practicable, but not more than 4 weeks after the tendons inside the

ducts have been stressed, and the Engineer’s permission to

commence grouting has been obtained. If due to the requirements of

the stressing procedure, tendons cannot be grouted within 4 weeks

the sheathing shall be sealed to protect the tendons from corrosion.

(d) Injection shall be continuous and slow enough to avoid producing

segregation of the grout. The method of injecting grout shall ensure

complete filling of the ducts and complete surrounding of the steel.

Grout shall be allowed to flow from the free end of the duct until its

consistency is equivalent to that of the grout injected. The opening

shall then be firmly closed. Any air vents shall be closed in a similar

manner one after the other in the direction of flow. The injection

tubes shall then be sealed off under pressure until the grout has set.

(e) The filled ducts shall not be subjected to shock or vibration within 1

day of grouting. Not less than 2 days after grouting the level of grout

in the injection and vent tubes shall be inspected and made good as

necessary.

(f) The Contractor shall keep full records of grouting including the date

when each duct was grouted, the proportion of the grout and any

admixtures used, the pressure, details of any interruptions and

topping up required. Copies of these records shall be supplied to the

Engineer within 3 days of completing grouting.

3.7 Protection of Prestressing Anchorages

(a) As soon as possible after tensioning and grouting are completed,

exposed end anchorages, strands and other metal accessories shall

be cleaned of rust, misplaced mortar, grout and other such materials.

(b) Immediately following the cleaning operation the entire surface of the

anchorage recess and all exposed metal shall be thoroughly dried and

uniformly coated with an epoxy bonding agent conforming to AASHTO

M235 Class III in accordance with the manufacturer’s

recommendations.

(c) The anchorage recess shall then be filled with an approved non-

shrinkage mortar. The mortar shall not contain aluminium powder,

iron particles, chlorides, sulphates, fluorides or nitrates.

(d) Where the protection will form part of the exposed works, the

anchorage recess shall be filled with concrete of the same quality and

colour as that of the adjacent concrete and shall be applied and cured

in accordance with these specifications or as may be required by the

Engineer.



(e) Exposed surfaces of anchorages not in an anchorage recess shall be

coated for corrosion protection with a coal tar epoxy or equivalent as

approved by the Engineer. Prior to coating, all surfaces shall be wire

brushed to remove all loose rust, mill scale or other deleterious

substances, and the surfaces cleaned with a suitable solvent to

remove oil and grease.

3.8 Superstructure Construction

(a) This work consists of the setting of temporary bearings if applicable,

pre-cast girders in fabrication yard, post-tensioning at site, and

setting of the superstructure on permanent bearings.

(b) The Contractor shall submit a construction schedule showing in

chronological order every phase and stage of erection and

construction of the superstructure.

(c) Construction joints will be limited to the locations shown on the

drawings.

(d) Surfaces of the girder joints shall be prepared in accordance with the

requirements of Specification - Concrete and Concrete Structures

immediately prior to the placement of concrete for joints

construction.

(e) For placement of closure concrete between girders, the girders shall

be fixed to prevent rotation or movement of one girder relative to the

other. The system for locking the girders and forming for the closure

and the procedure for placing the concrete for the closure shall be

such that the concrete after the initial set shall not be subjected to

tension which could cause cracking.

(f) The Contractor shall prepare a table of elevations and alignments

required at each stage of erection as detailed on the drawings, at the

points listed below or alternate points of his choosing for submission

to the Engineer.

* One of the lowest corners at the top surface of any temporary bearing pads to be used as datum during erection and to establish a reference point with the actual elevations and alignment required of the permanently positioned superstructure.

* All corners and cent re line of the top slab of pier to establish grade and crown.

* Two points on the longitudinal centre line of each pier cross section, one on each edge, to establish alignment.

* One point on the longitudinal centre line and, at least, one corner of each girder along every joint between girders to establish elevations and alignment at every stage of erection.

(g) The temporary bearing pads at the piers, if required shall be carefully



placed. The top surfaces of these pads shall have the correct

elevations, alignments and slopes as required in the drawings. Shims

may be used underneath the pads to accomplish accuracy. The

Contractor shall also devise and provide measures to hold temporary

bearing pads in position while the pier segment is being cast.

(h) The Contractor shall check the elevations and alignment of the

structure at every stage of construction in accordance with his

approved setting out procedures and shall maintain a record of all

these checks and of all adjustments and corrections made.

3.9 Curing

3.9.1 General

Except as specified herein or otherwise approved, wet (water) curing shall

be provided in compliance with the requirements in Specification -

Concrete and Concrete Structures. If the Contractor elects to cure by any

other method, the method and details shall be subject to the approval of

the Engineer. 3.9.2 Steam Curing

A steam curing process complying with the following conditions may be

used as an alternative of water curing, if proposed by the Contractor and

subsequently approved by the Engineer.

(a) The casting bed for any unit cured with steam shall be completely

enclosed to prevent steam from escaping and exclude the outside

atmosphere.

(b) Two to four hours after placing concrete and after the concrete has

undergone initial set, the first application of steam shall be made. If

retarding admixtures have been used, the duration before application

of the steam shall be increased to four to six hours.

(c) Water curing methods shall be used from the time the concrete is

placed until steam is first applied.

(d) The steam shall have a relative humidity of 100% to prevent loss of

moisture and to provide moisture for proper hydration of the cement.

(e) Steam shall not be directly applied to the concrete. During the

application of the steam, the ambient air temperature shall increase

at a rate not exceeding 22oC per hour until the maximum

temperature is reached and shall be held until the concrete has

reached the desired strength.

(f) In discontinuing the steam application, the ambient air temperature

shall not decrease at a rate exceeding 22oC per hour until the

temperature has reached 10oC above the temperature of the air to

which the concrete will be exposed.



(g) The maximum curing temperature shall be from 60oC to 67oC.

3.10 Handling, Transport and Storage

(a) Pre-cast pre-stressed concrete shall not be moved from the casting

position, or transported, until the concrete has attained a compressive

strength of 90% of the specified 28-day strength.

(b) Extreme care shall be exercised in handling and moving concrete

members.

(c) Pre-cast girders and slabs shall be transported in an upright position,

shock shall be avoided and the points of support and directions of the

reactions with respect to the members shall be approximately the

same during transport and storage as when the members is in its final

position. If the Contractor deems it expedient to transport or store

pre-cast pre-stressed units in other positions than this, it shall be done

at his own risk after notifying the Engineer of his intention to do so.

Any unit considered by the Engineer to have become substandard

shall be rejected and replaced by an acceptable unit at the

Contractor’s expense.

3.11 Marking of Precast Prestressed Members

Each pre-cast pre-stressed member shall be uniquely and permanently

marked so as to show its type and date of casting.

3.12 Erection of Pre-cast Beams

(a) Confirmation of position.

Prior to the erection of the beams the Contractor shall survey the

positions of the supporting columns and confirm with the Engineer on

the positions, both horizontal and vertical, of the supports.

The Contractor shall, at his own expense, make all necessary

adjustments to the bearing seating and beam length to ensure that

completed decks are true to line and level.

Any proposed deviation of beam length from that given in the drawings

shall be agreed by the Engineer before the beam is cast.

(b) Erection

The Contractor shall submit a full method statement for his proposed

methods for lifting and placing beams in their permanent position. The

method statement shall be submitted to the Engineer for his approval

within one month of the commencement date.

The statement shall particularly include but not be limited to the use of

lifting and transfer gantries supported on the new structure and

particular locations such as the start of erection from the embankment

and work at the Ong Nhieu river where temporary bridging may be

used. The statement shall include full details of the equipment to be



used to handle beams and to incorporate them into the structure. The

method statement shall be accompanied by full structural calculations

and appropriate workshop drawings for each stage of the procedure.

The calculations shall be appropriate for such temporary works and

shall take into full consideration all temporary loading cases arising

from the procedures, the prevailing conditions at the site, in particular

likely wind loading, and the nature of the existing ground. The

Contractor shall carry out all additional soils investigation necessary to

confirm his assumptions concerning the nature of the existing ground.

The calculations and drawings shall be certified and stamped by a

qualified structural engineer experienced in the preparation of such

details.

The details shall include consideration of the effect of each stage of the

procedure on the completed permanent works on which the gantry is to

be mounted and operated. The procedures for lifting and transferring

the beams into position and the order of erection of the beams shall be

such that the eccentricity of loading on the completed permanent

works (supporting piers and the foundations) is minimized.

When beams are being placed in position they shall be braced against

overturning before being released by the crane or other lifting devices.

Beams shall be prevented from moving laterally during the placing of

in-situ concrete.

The lifting and placing of beams will not be permitted to commence

until such time as the Contractor’s method statement, calculations and

shop drawings have been reviewed and approved by the Engineer.

3.13 Tolerances for Pre-stressed Concrete Structures

The tolerances listed in Table 1 are the allowable deviations for pre-stressed

concrete structures. These tolerances will be included in assessments for the

acceptance of work.

Table 1 Acceptance Tolerances of Pre-stressed concrete structures

Tolerance

Length 5 mm

Center Location 5 mm

Surface levels of Slab 10 mm

Surface level of base of hand-railing 5 mm

Width & Depth 10 mm

Compressive StrengthRefer subsection 06100

Surface Irregularity by 3m straight edge

5 mm



Bowing

3.14 Testing frequancies

Testing frequencies shall be accordance with Vietnamese Standard: 22TCN 389-07; 22TCN 247-98 or other international standard subject equivalence being demonstrated by the Contractor and the satisfaction of the Engineer of the Vietnamese standard shall apply:

Item Test Description Test Frequency Remark

1 TCXDVN 389-07: Precast prestressed concrete products - Technical requirement and acceptance

a


+ Cement Article 4.1.1 + Quality of aggregate for concrete Article 4.1.2 + Water for concrete Article 4.1.3

+ Others requirement index for concrete chloride ion, additive cement Article 4.15 ; 4.2

+ Reinforcement for precast prestressed concrete


Strength concrete requirement Article 4.3 Precast concrete anchor Article 4.5 Tensioning requirement Article 4.6 Construction tolerance Article 4.7; 4.8; 4.9


2

22TCN 247-98: Prestressed concrete beam - Code of Construction and acceptance procedure. Article 5

a


+ Cement Article 2.1 + Sand Article 2.2 + Quality of aggregate for concrete Article 2.3 + Water for concrete Article 2.4

+ Others requirement index for concrete : additive cement Article 2.5

+ Reinforcement for precast prestressed concrete Article 2.6; 2.7

+ Conduit Article 2.8 + Lubrication in conduit Article 2.9 + Tensioning Article 2.10 + Epoxy liquid Article 2.11




Constrcution for reinforcement & precast prestressed reinforcement Chapter III

Tightening of steel wire ropes bed, formwork, falsework Chapter IV

Tightening of steel wire ropes work

Chapter V (Include Pretensioning Method & Post-tensioning Method)

Beam casting & finishing Chapter VI

cAfter construction period: (For acceptance of construction works) Chapter VII



(1) Pre stressed Pre-cast Members

The quantity of pre-stressed pre-cast concrete members shall be

measured for payment by the number of pre-cast pre-stressed concrete

structural members of each length or type fabricated, hauled, erected

and installed in place, completed and accepted. Each member shall

include the concrete, reinforcement and pre-stressing steel, inserts,

boxouts and any other material or incidental work contained in or

attached to the above members.

(2) Cast in situ, Post-Tensioned Members

Cast in situ, Post-tensioned concrete members shall be measured for

payment by the number of cubic meters of concrete, the weight of

reinforcing steel and the weight of tendons (including duct,

anchorages, grouting etc.) respectively. For concrete, reference is

made to Specification - Concrete and Concrete Structures and for

reinforcing steel reference is made to Specification - Reinforcing Steel.



the contract price per unit of measurement for the pay items of the Bill

of Quantities listed below.

(b) Payment shall be full compensation for the work prescribed in this

section, and for furnishing all labor, materials, tests, tools, equipment

and any incidentals to complete the work as shown on the Drawings, as

required by these Specifications, and/or as directed by the Engineer.

(c) Payment for Tendons of Post Tensioning Members shall include the work

of tensioning, grouting, anchorages, ducts and all required testing for

materials.

Pay

Item

Description Unit



07400-01 Super T Girder type 1-1, type 1-2, type 1-3 Nos

07400-02 Super T Girder type 2 Nos



07400-05 Super T Girder type 5 (skew girder) Nos

07400-06 Super T Girder type 6 (skew girder) Nos


North – South Expressway Construction Projec Tender documents(Ho Chi Minh – Dau Giay Section) Contract Package 1A

SECTION 07500 - REINFORCING STEEL

TABLE OF CONTENTS

1. DESCRIPTION....................................................................89

2. MATERIAL REQUIREMENTS.................................................892.1 Reference Standards.....................................................................892.2 Material for Reinforcing Steel........................................................89

2.2.1 Reinforcing Bars..............................................................................................892.2.2 Spiral Reinforcement Steel..............................................................................892.2.3 Substitution of different size...........................................................................902.2.4 Welded Steel Wire Fabric.................................................................................90

3. CONSTRUCTION REQUIREMENTS........................................903.1 Handling and Placing Reinforcement..............................................903.2 Steel Quality and Supply................................................................903.3 Bar Lists and Bending Diagrams.....................................................913.4 Fabrication....................................................................................91

3.4.1 Bending...........................................................................................................913.4.2 Hooks and Bend Dimensions...........................................................................91

3.5 Fixing of Reinforcement Steel........................................................913.6 Splicing of Bars.............................................................................92

3.6.1 Lapped Splices................................................................................................933.6.2 Welded Splices................................................................................................933.6.3 Mechanical Coupler.........................................................................................93

3.7 Splicing of Mesh or Mats................................................................933.7 Testing frequencies.......................................................................93


Volume 3 – Technical Specification Reinforcing Steel- 88 -


1. DESCRIPTION

This Specification Section describes the requirements and provisions for the

supply, bending, fabrication and placing of steel reinforcement of the type,

size, shape and grade required in accordance with the drawings as specified

or as may be required by the Engineer.




the works covered by this Specification Section.

TCVN 1651:2008

Steel for the reinforcement of concrete

AASHTO M31 Deformed and Plain Billet-Steel Bars for Concrete Reinforcement

AASHTO T68 Distillation of Cut-Back Asphaltic (Bituminous) Products

AASHTO M164M

High-Strength Bolts for Structural Steel Joints

AASHTO M232 Zinc Coating (Hot-Dip) on Iron and Steel Hardware

ASTM A82 Cold-Drawn Steel Wire for Concrete Reinforcement

ASTM A153 Zinc-Coating (Hot-Dip) on Iron and Steel Hardware

ASTM A615 Deformed and Plain Billet-Steel Bars for Concrete Reinforcement

ASTM A185 Welded Steel Wire Fabric for Concrete Reinforcement


ACI 315 Details and Detailing of Reinforcement

2.2 Material for Reinforcing Steel

2.2.1 Reinforcing Bars

All reinforcing steel bars shall be deformed billet steel and shall meet the

requirements of AASHTO M31 (ASTM A615), Grade 60 or equivalent,

except for plain round reinforcing bars which shall be provided in

accordance with AASHTO M31 (ASTM A615), Grade 40 or equivalent as

called for in the reinforcing schedule. Testing shall be in accordance with

AASHTO T68. Unit stress calculations for bars having an area differing by

6 percent or more from the nominal bar area shall be made using the

measured bar area. 2.2.2 Spiral Reinforcement Steel

Spiral reinforcement steel shall comply with the requirements of ASTM

A615, Grade 40 [300 MPa] for spiral reinforcement in reinforced concrete



compression members. 2.2.3 Substitution of different size

(a) Substitution of bars of different size will be permitted only upon the

specific approval of the Engineer, and the substitute bars shall

provide a steel area equal to or larger than that called for in the

drawings. The Contractor shall submit the details of the unit weight

for each kind and size of substitute bar for the purposes of

Measurement and Payment.

(b) Number-designated bars not equivalent in sectional area to bars with

specified size in millimeters may be substituted with bars having the

closest designated number and sectional area, and their spacing shall

be adjusted to provide the same area per unit spacing. Substitution

of bars of which specified size in millimeters are not readily available

from the Contractor’s source may be made on the same basis. All bar

substitutions shall be subject to the approval of the Engineer.

2.2.4 Welded Steel Wire Fabric

Welded steel wire fabric shall comply with the requirements of ASTM A185

and shall be as indicated on the drawings. Welded fabric shall be placed

as recommended by the Concrete Reinforcing Steel Institute (CRSI) Manual

of Standard Practices.


3.1 Handling and Placing Reinforcement

All reinforcement steel shall be protected as far as practicable from

mechanical injury or surface deterioration, from rusting or other causes

from the time of shipment until it is placed. Reinforcement steel stored at

the site shall be laid on wood floors or pillows suitably spaced so that no

reinforcement steel shall be laid upon or come in contact with the ground.

When the weather is dry and the time for storage before installation is

limited, housing may be omitted, but if rainy or exceptionally humid

weather occurs or is anticipated, bars shall be stored under cover.

3.2 Steel Quality and Supply

(a) Representative samples of all reinforcement steel that the Contractor

proposes to use in the Works must be submitted together with the

manufacturer’s certificates stating clearly for each sample the place of

manufacture, expected date and size of deliveries to the Site, and all

relevant details of composition, manufacture, strengths and other

qualities of the steel before work is commenced to the Engineer for his

approval.

(b) In the event a reinforcement steel sample under test fails to meet the

specification requirements at any time, or the Engineer considers that

samples which were presented to him for test were not truly



representative, or if it becomes apparent that reinforcement steel

which has not been approved has been used on the Works, the

Engineer may instruct the Contractor to break out and remove

completely all such sections of the work already constructed using

such suspect reinforcement steel.

(c) All testing of reinforcement steel bars shall meet the requirements and

specification limits of the ASTM/AASHTO designation for the particular

size, and grade of steel.

3.3 Bar Lists and Bending Diagrams

The Contractor shall provide detailed bar lists and bending diagrams to the

Engineer for his review and approval. Fabrication and bending of

reinforcement shall not begin until such lists have been approved. Any

expense incidental to the revision of material furnished in accordance with

such lists and diagrams to make it comply with the design drawings shall be

borne by the Contractor.

3.4 Fabrication

3.4.1 Bending

Bar reinforcement shall be cut and bent to the shapes shown on the

Drawings. Fabrication tolerances shall be in accordance with ACI 315. All

bars shall be bent cold, unless otherwise permitted. Bars partially

embedded in concrete shall not be field bent except as shown on the

drawings or as specifically permitted. 3.4.2 Hooks and Bend Dimensions

The dimensions of hooks and the diameters of bends measured on the

inside of the bar shall be as shown on the drawings. When the dimensions

of hooks or the diameter of bends are not shown, they shall be in

accordance with Division I, Article 8.23 of the AASHTO Standard

Specifications for Construction of Roads and Bridges or ACI 318 Building

Code Requirements for Reinforced Concrete

3.5 Fixing of Reinforcement Steel

(a) Reinforcement steel shall be assembled to the shapes and dimensions

as indicated on the drawings. The bars shall be of the cross-sectional

areas indicated and shall be fixed rigidly and accurately in the forms in

the positions indicated on the drawings. The bars shall be firmly bound

together at intersections to ensure that the reinforcement framework

as a whole shall retain its shape, and the framework shall be so

temporarily supported as to retain its correct position in the forms

during the process of depositing and consolidating the concrete. The

end of all tying wires shall be turned into the main body of the concrete

and not allowed to project towards the surface. Spacing blocks shall be

of pre-cast concrete of a strength at least equal to that of concrete



being placed. They shall be as small as practicable and shall be

securely fixed in position by means of wires cast into them. They shall

be soaked with water immediately prior to concreting.

(b) No temporary metal supports to the reinforcement steel will be allowed

to be incorporated in the finished concrete, and metal clips or supports

shall not be placed in contact with forms for exposed surfaces. Use of

plastic supports will not be allowed.

(c) Clear cover for all reinforcement shall be as indicated on the drawings.

Where no cover is indicated it shall be 50mm or such other dimension

approved by the Engineer.

(d) At the time of concreting, all reinforcement steel shall have been

thoroughly cleaned and free of all loose rust, scale, mud, oil or any

other coatings that might destroy or reduce the concrete bond and it

shall also have been cleaned of all set or partially set concrete which

may have been deposited during previous concreting operations.

(e) The placing of all reinforcement steel bars shall be checked by the

Engineer and in no case shall concrete be placed around any

reinforcement steel that has not been approved by the Engineer. The

insertion of bars into, or the removal of bars from concrete already

placed, will not be permitted. Reinforcement steel temporarily left

projecting from the concrete at the joints shall not be bent without the

prior approval of the Engineer.

(f) Dowels shall project a minimum of 40 bar diameters unless otherwise

indicated on the drawings. Metal supports which extend to the surface

shall not be used. Placing bars on layers of fresh concrete as the work

progresses and adjusting bars during the placing of concrete will not be

permitted.

(g) Main reinforcement steel carrying determinate stresses shall be spliced

only where indicated on the drawings or on approved Shop Drawings.

(h) The minimum spacing centre to centre of parallel bars shall be 2.5

times the diameter of the bar, but in no case shall the clear distance

between the bars be less than 1.5 times the maximum size of the

coarse aggregate in the concrete.

(i) Bundled reinforcement shall be tied together at a spacing not

exceeding 1.80 meters.

3.6 Splicing of Bars

All reinforcement shall be furnished in full lengths as indicated on the

drawings unless otherwise approved by the Engineer. Except for splices

shown on the drawings and splices for 16mm or smaller bars, splicing of

bars will not be permitted without the approval of the Engineer. Splices shall

be staggered as far as possible.



3.6.1 Lapped Splices

Lapped splices shall be of the lengths shown on the drawings. If not

shown on the Drawings, the length of lapped splices shall be no less than

35 bar diameters. The bars in lapped splices shall be placed and wired in

such as manner as to maintain the minimum concrete cover and the

minimum spacing between the bars as detailed in this specification. 3.6.2 Welded Splices

Welded splices shall be used only if specified on the drawings or if

approved by the Engineer. Where approved welding shall conform to the

Structural Welding Code, Reinforcing Steel, AWS D1.4 of the American

Welding Society and applicable special provisions. Welding of

reinforcement steel will be allowed if the chemical composition of the steel

exceeds the percentages shown in Table 1.

Table 1 Reinforcing Steel ComponentsChemical Composition Percent

Carbon (C) 0.30

Manganese (MA) 1.50

Carbon Equivalent (C. E. ) 0.55

3.6.3 Mechanical Coupler

(a) Splices made with mechanical couplers shall be used only if detailed

on the drawings or previously approved by the Engineer in lieu of

welding. Such couplers shall develop in tension or compression as

required, at least 125 percent of the specific yield strength of the bar.

(b) When requested by the Engineer, up to two field splices out of each

100, or portion thereof, placed in the work and chosen at random by

the Engineer, shall be removed by the Contractor and tested to 125

percent of the specified yield strength.

3.7 Splicing of Mesh or Mats

Sheets of mesh or bar mat reinforcement shall be spliced by overlapping

sufficiently to maintain a uniform strength and shall be securely fastened at

the ends and edges. The lap shall not be less than one mesh in width plus

50 mm.


Testing frequencies (using for material testing) shall be accordance with

Vietnamese Standard: TCVN 1561-2008 or other international standard

subject equivalence being demonstrated by the Contractor and the



satisfaction of the Engineer of the Vietnamese standard shall apply:

Item Test Description Test Frequency Remark

1TCVN 1561-1: 2008: Steel for reinforcement of concrete - Plain bar.

Material testing: (for material approval)

Sampling & method for testing Article 11.3.2.2

Other testing & frequency for testing

Article 11.3.3

2TCVN 1561-2: 2008: Steel for reinforcement of concrete - Ribbed bar.

Material testing: (for material approval)

Sampling & method for testing Article 8; 9

Other testing & frequency for testing

Article 12.3.3



Reinforcing steel shall be measured for payment by tons for both deformed

bars, plain bars, based on the total computed weight for the sizes and

lengths of bars as indicated in the reinforcing schedules and as approved by

the Engineer.


(a) Reinforcing Steel Bars shall be paid for in accordance with the

applicable unit prices of the pay items of the Bill of Quantities listed

below. Payment shall be full compensation for all labour, materials,

tools, equipment and appurtenances for the complete supply and

installation of all reinforcement steel bars.

(b) No separate payment shall be made for clips, wires, separators, wire

chairs, and other material used in fastening the reinforcement in place.

In the event that bars are substituted upon the Contractor’s request

and as a result more steel is used than specified, only the amount

specified shall be included in the quantity for payment.

(c) When laps are made for splices for the convenience of the Contractor,

in addition to those indicated on the drawings the extra steel shall not

be included for payment.

(d) For computing the weight of reinforcement steel bars for payment, The

Contractor shall be comply with the Standard Unit Weight Table

provided according with table 2 TCVN 1651-1: 2008 (for plain bar) &

table 2 TCVN 1651-2:2008 (for ribbed bar)

Table 2 – TCVN 1561-1:2008 (Steel for the reinforcement of concrete – part 1: Plain bar)



Title diameter d,mm

Cross section area mm2, An

Theory quantity of 1m length

Requirement (kg/m)

Tolerance (%)

6 28.3 0.222 ±8

8 50.3 0.395 ±8

10 78.5 0.617 ±6

12 113 0.888 ±6

14 154 1.21 ±5

16 201 1.58 ±5

18 254.5 2.00 ±5

20 314 2.47 ±5

22 380 2.98 ±5

25 490.9 3.85 ±4

28 615.8 4.83 ±4

32 804.2 6.31 ±4

36 1017.9 7.99 ±4

40 1256.6 9.86 ±4

An = 0.7854 x d2

Unit weight per length = 7.85 x 10-3 x An

Table 2 – TCVN 1561-2:2008 (Steel for the reinforcement of concrete – part 2: Ribbed bar)

Title diameter d,mm

Cross section area mm2, An

Theory quantity of 1m length

Requirement (kg/m)

Tolerance (%)

6 28.3 0.222 ±8

8 50.3 0.395 ±8

10 78.5 0.617 ±6

12 113 0.888 ±6

14 154 1.21 ±5

16 201 1.58 ±5

18 254.5 2.00 ±5

20 314 2.47 ±5

22 380.1 2.98 ±5

25 491 3.85 ±4

28 616 4.84 ±4

32 804 6.31 ±4

36 1017.9 7.99 ±4

40 1257 9.86 ±4

50 1964 15.42 ±4If diameter of Ribbed bar is greater than 50mm, it is recommended to have agreement between Manufacturer and Purchaser, and tolerance allowable for



each ribbed bar must be ±4% An = 0.7854 x d2

Unit weight per length = 7.85 x 10-3 x An


07500-01 Reinforcing Steel Ton



SECTION 07600 - BRIDGE BEARINGS

TABLE OF CONTENTS

1. DESCRIPTION....................................................................98

2. MATERIAL REQUIREMENTS.................................................982.1 Reference Standards.....................................................................982.2 Submittals....................................................................................99

3. ELASTOMERIC BEARINGS.................................................1003.1 General.......................................................................................1003.2 Materials.....................................................................................100

3.2.1 Elastomeric Materials....................................................................................1003.2.2 Internal Steel Laminates...............................................................................1013.2.3 Laminated Elastomeric Bearing Pads............................................................101

4. MECHANICAL BEARINGS..................................................1034.1 Packaging, Handling, and Storage of Mechanical Bearings............103

5. DOWELS.........................................................................104

6. BEARING INSTALLATION...................................................104

7. TESTING OF BEARINGS....................................................1057.1 Mechanical Bearing Tests.............................................................1057.2 Elastomeric Bearings...................................................................1067.3 Rejection of Bearings...................................................................106

8. MEASUREMENT AND PAYMENT.........................................1078.1 Method of Measurement..............................................................1078.2 Basis of Payment.........................................................................107

Volume 3 – Technical Specification Waterproofing- 97 -


1. DESCRIPTION

This Specification Section describes the requirements and procedures for the

supply and installation of bridge bearing pads as indicated on the drawings,

or as may be directed by the Engineer.



AASHTO Standard Specifications for Highway Bridges and the following

Standards in their latest edition shall be particularly applied to the works

covered by this Specification Section.

AASHTO M183 Structural Steel

ASTM A36 Carbon Structural Steel

ASTM A123 Zinc (Hot-Dip Galvanized) Coating on Iron and Steel Products

ASTM A570 Steel, Sheet and Strip, Carbon, Hot-Rolled, Structural Quality


ASTM C881 Epoxy-Resin-Base Bonding Systems for Concrete

ASTM C1107 Installation of Load Bearing (Transverse and Axial) Steel Studs and Related Accessories

ASTM D412 Vulcanized Rubber and Thermoplastic Rubbers and Thermoplastic Elastomers Tension

ASTM D429 Rubber Property-Adhesion to Rigid Substrates

ASTM D518 Standard Test Method for Rubber Deterioration-Surface Cracking ASTM D573 Rubber - Deterioration in an Air Oven

ASTM D746 Brittleness Temperature of Plastics and Elastometers by Impact

ASTM D1149 Rubber Deterioration - Surface Ozone Cracking in a Chamber

ASTM D2240 Rubber Property - Durometer Hardness

ASTM D3182 Materials, Equipment, and Procedures for Mixing Standard Compounds and Preparing Standard Vulcanized Sheets

ASTM D3183 Preparation of Pieces for Test Purposes from Products

ASTM D3184 Evaluation of NR (Natural Rubber)

ASTM D3185 Evaluation of SBR (Styrene-Butadiene Rubber) Including Mixtures With Oil

ASTM D3186 Rubber-Evaluation of SBR (Styrene-Butadiene Rubber) Mixed With Carbon Black or Carbon Black and Oil

ASTM D3187 Evaluation of NBR (Acrylonitrile-Butadiene Rubber)

ASTM D3188 Evaluation of IIR (Isobutene-Isoprene Rubber)

ASTM D3189 Evaluation of Solution BR (Poly-butadiene Rubber)



ASTM D3190 Evaluation of Chloroprene Rubber (CR)

ASTM D3192 Carbon Black Evaluation in NR (Natural Rubber)

ASTM D3192 Carbon Black Evaluation in NR (Natural Rubber)

ASTM D4014 Plain and Steel-Laminated Elastomeric Bearings for Bridges

SAE 1020 Specifications for Rolled Strip. Specifications for Finish and Gauge

2.2 Submittals

The Contractor shall prepare and submit the following to the Engineer for

his approval. The Contractor shall obtain the approval of the Engineer

before beginning fabrication of the bearings.

(a) Certification by the manufacturer that the elastomer in the

elastomeric bearing pads to be provided conforms to all of the

requirements indicated in these Specifications. The certification shall

be supported by a certified copy of the results of tests performed by

the manufacturer upon samples of the elastomer to be used in the

pads.

(b) Certification by the manufacturer that the bearing devices to be

provided have been widely applied in other projects, listing the project

name, country and bearing codes and properties.

(c) Drawings for the bearings prepared according to Section 18 of the

AASHTO Standard Specifications for Highway Bridges Division II,

Volume II, or equivalent method approved by the Engineer. The

drawings shall show all details of the bearings including the material

proposed for use and confirmation that the proposed bearings have

been designed to comply with the loading requirements detailed in the

drawings.

(d) Shop drawings and calculations demonstrating the compliance of all

bearings with the schedule shown on the drawings.

(e) Detailed statement describing the procedures for packaging, handling

and storage of the bearing devices to be used for the Project.

(f) Detailed schedule for all the required testing of materials or bearing

devices to be used for the Project.

(g) Detailed statement of the method for construction and installation of

the bearing devices to be used for the Project.

(h) Once the Engineer has approved these methods, they shall not be

changed without prior approval by the Engineer.



3. ELASTOMERIC BEARINGS

3.1 General

(e) Elastomeric bearings shall consist of laminated elastomeric pads or

assemblies of laminated elastomeric pads as indicated on the

Drawings and as specified herein.

(f) Variation in thickness of an individual elastomer lamination shall not

exceed 3 mm within the width or length of a bearing pad and the

variation in thickness of all elastomer laminations within a bearing pad

shall be such that each metal or fabric lamination will not vary by

more than 3 mm from a plane parallel to the top or bottom surface of

the bearing pad.

(g) The total out to out thickness of a bearing pad shall not be less than

the thickness indicated on the Drawings nor more than 6 mm greater

than that thickness. Variation of total thickness within an individual

bearing pad shall not exceed 3 mm.

(h) The length and width of a bearing pad shall not vary more than 3 mm

from the dimensions indicated on the Drawings.

(i) The bond between the elastomer and the steel laminate shall be such

that, when a sample is tested for separation, failure shall occur within

the elastomer and not between the elastomer and the steel.

3.2 Materials

(a) All materials used in the manufacture of the bearing assemblies shall

be new and unused with no reclaimed material incorporated into the

finished assembly. All bonding of components shall be done under

heat and pressure during the vulcanizing process. The bond shall be

continuous throughout the plan area with no air spaces greater than

0.25 mm within the bonding material. The bearing assemblies shall be

furnished as complete units from one manufacturing source.

(b) The materials for the elastomeric bearings and assemblies shall

comply with the following requirements:

3.2.1 Elastomeric Materials

The elastomic materials of the compounds shall be 100% virgin polychloroprene

synthetic rubber meeting the requirements of Table No.1. The properties of the

elastomeric compounds shall be determined from test specimens complying with

ASTM D3182 through D3190 inclusive and D3192. A variation of 10% in tensile

strength and ultimate elongation under “physical properties” will be permitted

when test specimens are cut from the finished product.

Volume 3 – Technical Specification Waterproofing- 100

-


3.2.2 Internal Steel Laminates

The internal steel laminates for the laminated elastomeric bearing pads shall be

rolled carbon steel sheets complying with ASTM A 570 or AASHTO N183 (ASTM

A36).

3.2.3 Laminated Elastomeric Bearing Pads

Laminated elastomeric bearing pads shall be individually molded to the required

size. Corners and edges may be rounded with a radius at the corners not

exceeding 9 mm and a radius at the edges not exceeding 6 mm. All edges of

the steel laminations shall be covered with not less than 4 mm and not more

than 6 mm of elastomer. The characteristics of the elastomeric bearing pads

shall be within the following listed tolerances:

TABLE No.1 - Requirements of Elastomeric Bearing Pads

ASTM Standard Physical Properties Value

D2240 Hardness, ASTM D2240 60 5D412 Tensile strength, min.kg/cm2

Ultimate elongation, min.%175425

Heat ResistanceChange in durometer hardness, max.points

+ 15

D573, 70 HR. @ 100oC

Change in tensile strength, max.% Change in ultimate elongation, max. %

- 15- 40

Compressive SetD395. Method B

22 hours @ 100 oC max. % 35

Ozone

D1149 100 pphm ozone in air by volume, 20% strain, 37.7 oC 1C, 100 hours mountingProcedure D 518, Procedure A

NoCracks

Adhesion to SteelBond made during vulcanization 80% R(Z1)

D429, A Bond Strength (per square cm) 2.8kgD429, B Peel Strength (per cm of width) 7 kg

Adhesion to TFEBond made during vulcanization

D429, B Peel Strength

Polychloroprene - Synthetic Rubber

ASTM Standard Physical Properties 60 DuroLow Temperature Test-Durometer ChangeBearing or sample to be exposed for 96 hrs. @-28 oC, 2 oC. (The specimen


-


shall have a 24 hr. conditioning period at room temperature prior to low temperature exposure). The durometer test shall be made at-28 oC on an unbuffed surface. Durometer hardness increase, Max. ASTM D2240, 30 second reading. Durometer to be placed in freezer with test specimen

+ 15(Z2)

D746 Brittleness temp., 3 min., at -40 oC No cracksStructural Steel. The internal steel laminates for the laminated elastomeric bearings shall be rolled mild steel sheets conforming to SAE 1020 or AASHTO M183.Laminated elastomeric bearings shall be individually molded to the required size. Corners and edges may be rounded with a radius at the corners not exceeding 9 mm and radius at the edges not exceeding 6 mm. All edges of the steel laminations shall be covered with not less than 3 mm and not more than 6 mm of elastomer. The dimensions of the elastomeric bearings shall be within the following listed tolerances:

Overall Vertical Rubber Dimension.Average total rubber thickness 32 mm or lessAverage total rubber thickness over 32 mm

-0, +3 mm

-0, +6 mm

Overall Horizontal Rubber Dimension90 cm or less 0, + 3 mm

Thickness of individual layers of elastomer (60 Durometer Only) 20%Variation from a plane parallel to the theoretical surface per 300 mm, tops 1.5 mm sides 6 mm Edge cover of embedded metallic laminate 4 mm min.

6 mm max.

The rubber laminates shall be of uniform integral units, capable of being

separated by mechanical means into separate, well-defined elastomeric layers.

The ultimate breakdown limit of the elastomeric bearing under compressive

loading shall be not less than 140 kgs/cm2. In addition to the requirements of

Table No. 1, the stress-strain relationship of the finished elastomeric bearings at

room temperature shall not exceed the following limitations.

CompressionStress 35 kgs/sq.cm 56 kgs./sq.cmStrain (Percent of total thickness of all elastomer laminations

5% 7%


-


(c) In addition, shear resistance of the bearing shall not exceed 2.1

kg/cm2 for 60 durometer, Table No. 1 compounds at 25% strain of the

total effective rubber thickness after an extended four-day ambient

temperature of -28 oC.

(d) The Contractor shall furnish to the Engineer a certification by the

manufacturer that the elastomer, in the elastomeric bearing pads to

be furnished conforms to all of the above requirements. The

certification shall be supported by a certified copy of the results of

tests performed by the manufacturer upon samples of the elastomer

to be used in the pads.

4. MECHANICAL BEARINGS

(a) Mechanical Bearings shall be pot type bearings. Movement bearings

will normally have sliding surfaces of stainless steel and

polytetrafluorethylene and may also have been fitted with guide bars

or keyways.

(b) Bearings shall have surface protecting in accordance with

requirements and procedures noted under Specification section

08800.

4.1 Packaging, Handling, and Storage of Mechanical Bearings

(a) Prior to shipment from the point of manufacture, bearings shall be

packaged in such a manner to ensure that during shipment and

storage the bearings will be protected against damage form handling,

weather, or any normal hazard.

(b) Each completed bearing shall have its components clearly identified,

be securely bolted, strapped or otherwise fastened to prevent any

relative movement, and marked on its top as to location and

orientation in each structure in the project in conformity with the

plans.

(c) Dismantling at the site shall not be done unless absolutely necessary

for inspection or installation.

(d) All bearing devices and components shall be stored at the work site in

an area that provides protection form environmental and physical

damage.

(e) When installed, bearings shall be clean and free of all foreign

substances.


-


5. DOWELS

(a) Steel dowels shall be provided and installed in accordance with

requirements and with accessories noted on the drawings.

(b) Dowels shall be smooth plain billet-steel bars conforming to

requirements of ASTM A615, 400 MPa and shall be zinc (hot-dip

galvanized) in accordance with ASTM A123.

(c) Dowels may be cast-insitu as shown on the drawings or drilled and

grouted with an approved epoxy compound.

(d) If dowels are drilled and grouted:

holes shall provide at least 10 mm in diameter greater than the largest diameter of the dowel;

holes shall be thoroughly cleaned with compressed air and water prior to grouting of dowels so as to remove all loose or extraneous materials;

the epoxy compound used shall be ASTM C881, Type IV or approved equivalent and mixed and placed in accordance with manufacture’s requirements.

6. BEARING INSTALLATION

(a) The bearings shall be clearly marked with their longitudinal and

transverse axes, their type number and their intended locations in the

Works.

(b) Unless otherwise approved by the Engineer bearing beds shall be of

non-shrink grout conforming to ASTM C1107, Grade A. Proposals for

the thickness and type of bearing plinths and beds shall be submitted

by the Contractor and approved by the Engineer in advance of

bearing installation.

(c) Bearings shall not be dismantled. Any transit bolts, straps or other

temporary fixing shall not be removed until the bearing is fixed in its

final position and the structure immediately above the bearing is in

place. Care shall be taken to ensure that all transit bolts, straps or

other temporary fixings are finally removed.

(d) All bearings shall be set horizontal in both directions and shall be

positioned so that the inscribed longitudinal axis is parallel to the

structure axis at the point of support, unless otherwise noted on the

Drawings.

(e) Any devices such as steel packs used to hold bearings level whilst

being fixed, must be removed so that the bearing seats only on its

mortar bedding.

(f) Where pre-cast beams and segments are placed on elastomeric


-


bearings, immediately prior to the placing of each beam and segment

the top of the bearing shall be coated with a sufficient thickness of

approved mortar to take up any irregularities between the surface of

the beams and segment and the bearings.

(g) The characteristics of all bearing shall be within the Manufacturer’s

tolerances and to the following tolerances:

Alignment, maximum departure from required vertical or horizontal

plane:

Entire assembly 1:400

Lower part of bearing 1:1000 relative to upper

Plan position

Laterally 3mm

Longitudinally 6mm

Center/Center Spacing 3mm

7. TESTING OF BEARINGS

The testing of selected bearings shall be arranged with the Engineer prior to

their inclusion in the Works. The testing shall be done at an independent

testing facility approved by the Engineer.

7.1 Mechanical Bearing Tests

(1) Vertical Proof Load Test of Complete Bearing

The vertical proof load shall be 1.5 times the maximum vertical load

specified in the bearing schedule. The proof load shall be maintained

for a minimum period of three minutes.

(2) Horizontal Proof Load Test of Complete Bearing

Bearings, which are required to resist lateral forces, shall be further

tested to 1.5 times the lateral load stated on the Drawings while

loaded in compression to the minimum vertical load shown on the

Drawings. The load shall be maintained for three minutes.

(3) Rotation test of Complete Bearing

(a) The bearings shall be tested in rotation to the value for rotation

shown on the Drawings while being loaded in compression to the

maximum vertical load shown on the Drawings. Bearings, which

are required to resist lateral forces, shall also have the specified

lateral load stated on the Drawings applied during this test.

(b) The direction of application of the lateral load and the axis of

rotation shall be compatible with the in-service loads and


-


rotational requirements. The lateral load shall be applied using a

calibrated sliding surface to minimize any frictional restraint. All

PTFE and stainless steel interfaces shall be lubricated prior to the

test. The test loads shall be maintained for three minutes.

7.2 Elastomeric Bearings

(1) Long-Duration Compression Tests on Bearings

Selected bearings shall be loaded in compression to 1.5 times their

maximum design load for a minimum period of 15 hours. If, during

the test, the load falls below 1.3 times the maximum design load, the

test duration shall be extended by the period of time for which the

load is below this limit. The bearing shall be examined visually at the

end of the test while it is still under load. If the bulging pattern

suggests laminate parallelism or a layer thickness that is outside the

specified tolerances, or poor laminate bond, the bearing shall be

rejected. If there are three or more separate surface cracks that are

greater than 0.08 in. (2mm) wide and 0.08 in. (2mm) deep, the

bearing shall be rejected.

(2) Shear Modules Tests on Material from Bearings

The shear modulus of the material in the finished bearing will be

evaluated by testing a specimen cut from the bearing using the

apparatus and procedure described in Annex-A of ASTM D4014, or, at

the discretion of the Engineer, a comparable non-destructive stiffness

test may be conducted on a pair of finished bearings. The shear

modulus shall fall within 15 percent of the specified value or within the

range for its hardness given in AASHTO Standard Specifications for

Highway Bridges, Article 14.3 of Division I, if no shear modulus is

specified. If the test is conducted on finished bearings, the material

shear modulus shall be computed from the measured shear stiffness

of the bearings, taking due account of the influence on shear stiffness

of bearing geometry and compressive load.

7.3 Rejection of Bearings

Any bearing that, as a result of the testing specified, exhibits any signs of

failure such as:

(a) Splitting or permanent deformation of the elastomer;

(b) Tearing, cracking or permanent deformation of the PTFE sliding

surface;

(c) Cracking or permanent deformation of the sealing ring or other part

of the bearing;

(d) Abrasive marks indicating abnormal contact between the metal

surfaces of the bearing plates or piston, and the pot;


-


(e) or does not comply with the requirements and tolerances of this

Specification Section, shall be rejected and shall be replaced

immediately.

(f) Bearings damaged during transport, installation or subsequent

construction operations shall also be liable for rejection and

replacement.



(a) The bearings shall be measured for payment by the number of each

type completed in place in accordance with the drawings, and

approved by the Engineer.

(b) Galvanized steel dowels installed and approved by the Engineer shall

not be measured separately.



the contract price per unit of measurement for the pay items of Bill of

Quantities listed below.


Section for the supply, bearing testing, fabrication, transport, coating

and placing of all materials, and for furnishing all labour, materials,

tests, tools, equipment and any incidentals to complete the work as

shown on the Drawings and as required by these Specifications, and/or

as directed by the Engineer. Payment shall also include full

compensation for bearing bedding and furnishing, fabricating,

transporting, coating and placing all galvanized steel dowel bars with

epoxy grout and proper placement of dowels and grout.


07600-01 Bearing Elastomeric Type (600 350

78) mm

set

07600-02

07600-03

Pot Bearing, bearing capacity 2000 KN

Non-shrinkage mortar

Set

Cu.m

07600-05 Bearing pad steel 2mm Ton

07600-06

07600-07

Set up elastic layer whole thickness is 2cm

Bitument

Sq.m

Cu.m

SECTION 07700 - WATERPROOFING


-


TABLE OF CONTENTS

1. DESCRIPTION..................................................................109

2. MATERIAL REQUIREMENTS...............................................1092.1 Reference Standards...................................................................1092.2 Deck Waterproofing Membrane....................................................1092.3 Bituminous Waterproofing Membrane...........................................1092.4 Submittals..................................................................................110

3. CONSTRUCTION REQUIREMENTS......................................1103.1 Product Delivery, Storage and Handling........................................1103.2 Preparation of Surface.................................................................1103.3 Application..................................................................................110

3.3.1 Deck Waterproofing Membrane.....................................................................1103.3.2 Bituminous Waterproofing Membrane...........................................................111



-


1. DESCRIPTION

The work under this Specification Section consists of the supply, transport

and installation of waterproofing membranes in accordance with the

information, procedures and details stated in this Specification Section and in

conformance with the drawings, and as required by the Engineer.

The Contractor shall apply bituminous membranes and deck waterproofing

membranes to all surfaces as indicated on the drawings, including but not

limited to wing walls, retaining walls, abutment walls, and similar

foundations, and to the bridge decks.





AASHTO

M243

Field Applied Coating of Corrugated Metal Structural

Plate for Pipe, Pipe Arches, and Arches

ASTM D41-05Asphalt Primer Used in Roofing, Damp proofing, and

Waterproofing

ASTM D173-

03

Bitumen Saturated Cotton Fabrics Used in Roofing and

Waterproofing

ASTM D449-

03

(Type III) Standard Specification for Asphalt Used in

Damp proofing and Waterproofing

ASTM D517-

98

(2003)

Standard Specification for Asphalt Plank

2.2 Deck Waterproofing Membrane

All the materials to be used for furnishing and installing the deck

waterproofing membrane shall be certified by the manufacturer and shall be

approved by the Engineer before they are used in the Works.

2.3 Bituminous Waterproofing Membrane

(a) The Contractor shall furnish to the Engineer certification from the

manufacturer that the bituminous waterproofing membrane system

has been used successfully in similar applications during the

preceding five years.

(b) The Contractor shall provide to the Engineer evidence that the applier

of the material is a qualified, experienced applier and is approved by

the manufacturer to apply his materials.

(c) Primer: The furnished primer material shall be in accordance with

ASTM-D41, or as approved by the Engineer.

(d) Mastic: The furnished primer material shall be in accordance with


-


AASHTO-M243, as applicable and as approved by the Engineer.

(e) Asphalt: Asphalt for mop coat shall be in accordance with ASTM D449,

Type III.

(f) Waterproofing fabric: Asphalt saturated fabric shall be in accordance

with ASTM D173.

(g) Asphalt plank: Material for asphalt plank, if used or if approved by the

Engineer, shall be in accordance with ASTM D517.

2.4 Submittals

The Contractor shall submit to the Engineer three samples of each type of

the materials he proposes to use in accordance with pertinent requirements

of the Specifications.

For bituminous mastic and primer, one-pint containers shall be submitted.

The Contractor shall submit to the Engineer certification that materials to be

provided comply with the requirements of this specification.


3.1 Product Delivery, Storage and Handling

(a) The Contractor shall deliver products to the job site in their original

unopened containers clearly labelled with the manufacturer’s name,

brand designation, type and class as applicable.

(b) The Contractor shall store products in an approved dry area and shall

protect them from contact with soil and from exposure to the elements.

Products shall be kept dry at all times.

(c) Products shall be handled in a manner that will prevent breakage of

containers and damage to products.

3.2 Preparation of Surface

(a) The surface to which the waterproofing is to be applied shall be

cleaned of all loose and foreign materials, dirt, grease or oil and shall

be dry. When necessary the Engineer may require the surface to be

scrubbed with water and a stiff brush, after which the surface shall be

allowed to dry before application of the primer.

(b) Concrete to which the deck waterproofing membrane is to be applied

shall be prepared in accordance with the manufacturer’s

recommendations.

3.3 Application

3.3.1 Deck Waterproofing Membrane

The deck waterproofing membrane shall be a proprietary waterproofing

system of the thickness indicated on the drawings and as approved by the

Engineer, and shall be applied in accordance with the manufacturer’s

recommendations.


-


3.3.2 Bituminous Waterproofing Membrane

The Contractor shall furnish and install the bituminous membrane as

specified herein to all surfaces indicated on the Drawings including, but

not limited to, abutment, wing-walls, retaining walls, and similar

foundations where directed by the Engineer. The work shall include the

supply and application of bituminous membranes on all surfaces specified

to receive waterproof membrane.

Concrete or other surfaces, which are to be protected by bituminous

membrane, shall be thoroughly cleaned before the primer is applied.

They shall then be brush or spray painted with two coats of tar or asphalt

primer for absorptive treatment. Below ground not less than two coats

shall be applied at a rate of 0.56 liters per square meter of surface.

On the well-primed surface one application of tar or asphalt seal coat shall

be applied by brush at a rate of 0.45 liters per square meter. Care shall be

taken to confine all paints to the areas to be waterproofed and to prevent

disfigurement of any other parts of the structure by dripping or spreading

of the tar or asphalt.



(a) Deck waterproofing membranes shall be measured for payment by

square meters actually completed in place in accordance with the

Drawings.

(b) No measurement and payment shall be made for bituminous

membranes applied on other concrete structures. All costs associated

with this work shall be considered as a subsidiary obligation and

requirement under the applicable concrete pay items in the Bill of

Quantities.



the contract price per unit of measurement for the pay items of the

Bill of Quantities listed below.


Section for the supply and installation of all the required membranes

for waterproofing including all labour, materials, tests, tools,

equipment and any incidentals to complete the work as shown on the

Drawings and as required by these Specifications, and/or as directed

by the Engineer.


07700 - 01 Waterproofing Membrane m2


-


SECTION 07800 - EXPANSION JOINT

TABLE OF CONTENTS

1. DESCRIPTION..................................................................113

2. MATERIAL REQUIREMENTS...............................................1132.1 Reference Standards...................................................................1132.2 Submittals..................................................................................1162.3 Approval of Materials..................................................................116

3. CONSTRUCTION REQUIREMENTS......................................1163.1 Method of Construction and Installation.......................................1163.2 Pre-moulded Joint Filler...............................................................1173.3 Joint Sealer.................................................................................117


Volume 3 – Technical Specification Expansion joint- 112 -

–


1. DESCRIPTION

This Specification Section describes the requirements for expansion and

fixed joints as indicated on the drawings, including pre-moulded joint filler

and joint sealer. The Contractor shall furnish all required materials and

install expansion joints, fixed joints, pre-moulded joint filler and joint sealer

in accordance with the details indicated on the drawings and as specified

herein. This work shall include the supply and installation or application of

all necessary hardware including anchor bolts and studs, sealants,

adhesives, epoxies, and other accessories.



The following Standards in their latest edition shall be particularly applied

to the works covered by this Specification Section.

AASHTO M297 Specification standard for Bridge expansion

jointAASHTO M183

ASTM A123Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

ASTM D395 Rubber Property—Compression Set

ASTM D412Vulcanized Rubber and Thermoplastic Rubbers and Thermoplastic Elastomer - Tension

ASTM D471 Rubber Property - Effect of Liquids

ASTM D994Preformed Expansion Joint Filler for Concrete (Bituminous Type)

ASTM D1149Rubber Deterioration - Surface Ozone Cracking in a Chamber

ASTM D2240 Rubber Property - Durometer Hardness

ASTM D6690Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt Pavements

(a) The elastomeric portion of the expansion joints shall be of the

compound known as neoprene which shall have the physical

properties as determined by the following ASTM requirements:

Standard Physical Properties Requirements

ASTM D412 Tensile strength 126kg/cm2 (min. )

ASTM D412 Elongation at break 400%

ASTM D2240 Hardness (Durometer A) 50 5

ASTM D395 Compression set(Method B) 22 hours at 70 oC

20%, max.

ASTM D1149 Ozone resistance: No cracks


–


Exposure to 100 ppm ozone for 70 hours @ 38°C sample under 20% strain

ASTM D471 Oil deterioration:Volume increase after immersion in ASTM Oil # 3 for 70 hours @ 100 °C

120%, max.

(b) The dimensions of the neoprene portion of the joint shall be correct

to zero millimeters under and plus 6-mm over in width and length,

and from zero millimeters under to plus 3-mm in thickness of the

exterior dimensions required on the drawings, measured at 21oC.

(c) The sealant for sealing joints between the expansion joint units,

along the edges of the expansion joint, and the bolts and plugs shall

be a high solid, one-part polyurethane based sealant that cures

quickly, without shrinkage, into a rubber with high elongation

characteristics and excellent recovery． Sealant shall be capable of

bonding to concrete, steel, and neoprene without the use of a

primer. When cured, the sealant shall possess excellent abrasion

resistance and shall resist attack by salt, oil, and road chemicals.

The sealant to be used shall meet the requirements of the

manufacturer of the neoprene expansion joint.

(d) When test specimens are cut from the finished product a 10-percent

variation in Physical Properties will be allowed.

(e) The flexible epoxy for filling voids around the nut fasteners shall

consist of a black two-component flexible epoxy sealant having the

following physical properties:

Base Material: Flexibilized Epoxy Resin

Weight/Liter(mixed materials):

1.05 kg/liter

Mixing Time: 2 min. @ 24°C with 50 strokes minimum

Pot Life: 10-15 minutes @ 24°C

Initial Cure: 4 hours @ 24°C

Final Cure: 48 hours @ 24°C

Shelf Life: 12 months minimum (components separate)

Hardness Shore A Durometer:

80 + 10

(f) Flexible epoxy shall be supplied either in cans or preassembled

cartridges. Flexible epoxy shall meet the requirements of the

manufacturer of the expansion joint. Flexible epoxy shall also be

compatible with and have the physical characteristics when cured,

similar to the neoprene of the joint.

(g) The adhesive/sealant bedding epoxy for bonding the expansion joint


–


to concrete or steel shall be supplied in pre-measured cartridges or

cans and shall consist of a grey, two-component flexible epoxy

having the following physical properties:

Base Material: Epoxy Resin

Color: Concrete Grey

Weight/Liter (Mixed Materials):

1.44 kg/liter

% Solids Content: 98 % minimum by weight

Mixing Time: 2 min. @ 24 ºC with 50 strokes minimum

Pot Life: 25-30 minutes @ 24°C

Initial Cure: 4 hours @ 24°C

Final Cure: 48 hours @ 24 ºC

Shelf Life: 12 months minimum (components separate)

Tensile Strength: 211 kg/cm2

Elongation: 7% @ 24 °C

Water Absorption: 1. 0% maximum

Bond Strength to concrete: Concrete fails before bond

(h) Structural steel anchors shall be fabricated and hot dip galvanized in

accordance with the requirements of ASTM A123.

(i) Anchor bolts for joint seals shall be hot dip galvanized in accordance

with ASTM A153 commercial grade bolts set in epoxy mortar in holes

cored in the deck in accordance with approved shop drawings.

(j) The surface of holes cored in the concrete shall be carefully

prepared to provide a cleaned textured surface to which the epoxy

mortar can successfully bond. Faces shall be mechanically tooled

until surface glaze and contamination have been removed; dusted

to remove all residues; dried thoroughly and then primed with

hydrophobic epoxy resin immediately prior to setting the anchor

bolts in epoxy mortar. Bolts shall be degreased with white spirit

alcohol and dried thoroughly. Coring and setting the anchor bolts

shall not be done until a minimum of 7 days after concrete is

poured.

(k) Epoxy mortar shall consist of a mixture of aggregate and epoxy

binder. Aggregate shall consist of clean, hard quartzite particles

with a maximum size of 2 millimeters. Aggregate shall be dried

until the moisture content is less than 0.2 percent by weight and

then shall be sealed in plastic containers until required for mixing on

site. Binder for epoxy mortar shall be two part, cold curing,

solventless epoxy produced by an approved manufacturer. Primer

shall be compatible with the epoxy resin binder and shall be

supplied by the same manufacturer. The type of resin selected shall


–


be that recommended by the manufacturer for this application and

shall meet the requirements of the supplier of the component on

which it is to be used.

(l) Components of the epoxies shall be proportioned, mixed, applied and

cured strictly in accordance with the manufacturer’s printed

recommendations. Mixing shall be carried out with an efficient

mechanical device which ensures that all components are fully

dispersed and wetted. The two parts of the epoxy binder for the

mortar shall be thoroughly mixed first without frothing and the

aggregate added progressively. Mixed epoxy mortar which has begun

to cure before it has been placed and compacted, will be rejected and

a fresh batch shall be mixed.

2.2 Submittals

(a) The Contractor shall submit to the Engineer, for his approval,

complete Shop Drawings of all expansion joints. The Shop Drawings

shall include a movement chart showing the total anticipated

movement of the structure and the required setting width of the

joint assembly at various temperatures. All movements due to

shrinkage, creep, mid-slab deflection, and similar data, may not be

incorporated into this chart but shall be considered by the

Contractor and approved by the Engineer prior to final installation

and adjustment.

(b) The Contractor shall provide to the Engineer for review and

approval manufacturer’s literature verifying that all materials to be

supplied conform to the requirements of these specifications.

(c) The Engineer may request the Contractor to furnish whatever

samples which may be required to perform any of the tests specified

as necessary to approve the material. The use of all joints to be

used in the work shall be subject to approval of the Engineer.

2.3 Approval of Materials

No materials shall be used or installed until they have been approved by

the Engineer.


3.1 Method of Construction and Installation

(a) The Contractor shall obtain installation instructions from the supplier

of the expansion joint material and comply with the instructions

provided for the installation of the joint. The adequacy of the joint

design and installation details shall be subject to the approval of

the Engineer. The Contractor shall obtain the technical assistance of

a field representative from the manufacturer of the joint during its

installation. Proper adjustment shall be made for temperature at


–


the time of installation.

(b) Concrete on which expansion joints are to be set shall be dry, clean

and free from dirt, grease, latency and contaminants; level and

sound with no broken or spilled concrete. No joint shall be placed

until the Engineer has inspected and approved the seat conditions.

(c) After coating the seat area with the specified sealant adhesive, the

joint shall be positioned over the anchor bolts and the nuts securely

tightened. All loose or long anchor bolts shall be corrected in a

manner approved by the Engineer.

(d) All joints between units, around connecting bolts, and cavity plugs

shall be carefully sealed with sealant in a neat workmanlike manner

to keep out water and protect against corrosion. Neoprene surfaces

to be in contact with sealant shall be buffed at the plant or wire

brushed prior to installation to provide a bonding surface for the

sealant.

(e) Prior to filling the space in the bolt wells, the Engineer shall inspect

the anchor bolts and the tightening of the nuts to the

manufacturer’s specified torque. Any wells sealed without the

Engineer’s approval shall be opened and resealed after approval at

the Contractor’s expense.

(f) The finished joint shall present a smooth, neat appearance with no

protruding bolts or rough joints. Excess sealant shall be wiped or

scraped away before it becomes hard.

3.2 Pre-moulded Joint Filler

(a) Pre-moulded joint filler shall conform to the requirements of ASTM

D994 　 with a nominal thickness of 20 mm. Joint filler must be

compatible with joint sealant.

(b) The filler for each joint shall be furnished in a single piece for the full

depth and width required for the joint. When the use of more than

one piece is required for a joint, the abutting ends shall be fastened

securely and held accurately to shape by stapling or other positive

fastening means.

3.3 Joint Sealer

(a) Joint sealer shall be in accordance with ASTM D6690.

(b) Each lot or batch of sealing compound shall be delivered to the job

site in the manufacturer's original sealed container. Each container

shall be marked with the manufacturer's name, batch or lot number,

and the safe heating temperature and shall be accompanied by the

manufacturer's certification stating that the compound meets the

requirements of this specification.


–




(a) Expansion Joints shall be measured for payment by linear meters of

the material installed and approved by the Engineer, measured

along the centre line of the joint.

(b) The length of the expansion joint shall be in accordance with the

drawings or as shown on the Shop Drawings.


(a) Payment for Item Expansion Joints shall be made in accordance with

the applicable unit prices of the pay items of the Bill of Quantities

listed below,

(b) Payment shall be full compensation for all materials, labour, tools,

equipment and appurtenances and execution of all work and any

incidentals required for the complete finishing and installation of all

the respective expansion joint items.

(c) Pre-moulded Joint Filler and Joint Sealer shall not be paid separately.

They shall be deemed to be included in the unit price of Expansion

Joint with full compensation for all materials, labour, tools,

equipment and appurtenances and execution of all work and any

incidentals required for the complete finishing and installation of

pre-moulded joint filler and joint sealer.

Pay Item

Description Unit

07800-01 Expansion joint lm


–



–


SECTION 07900 - BRIDGE DRAINAGE

TABLE OF CONTENTS

1. DESCRIPTION..................................................................121

2. MATERIAL REQUIREMENTS...............................................1212.1 Reference Standards...................................................................1212.2 Drain Pipes.................................................................................1212.3 Catch pit and Grating...................................................................1212.4 Fixing Brackets............................................................................1212.5 Submittals..................................................................................1212.6 Delivery, Storage and Handling....................................................1212.7 Installation..................................................................................122

3. MEASUREMENT AND PAYMENT.........................................1223.1 Method of Measurement..............................................................122

3.1.1 Catch pits and gratings.................................................................................1223.1.2 Drainage Pipe................................................................................................1223.1.3 Basis of Payment...........................................................................................122

Volume 3 – Technical Specification Bridge drainage- 120

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1. DESCRIPTION

This work consists of the provision and installation of the bridge drainage

system. Work shall be in accordance with the drawings subject to the approval

of the Engineer.





ASTM A53 Specification for pipe, steel, black and hot-dipped, zinc coated, welded and seamless.

ASTM A48 Specification for grey iron castings. JIS G 5501 Grey Iron Castings. JIS G 3442 Galvanised steel pipes for ordinary piping. JIS G 3101 Rolled steels for general structures

2.2 Drain Pipes

Pipe and fittings shall be of the size and types indicated on the drawings. They

shall be galvanized and comply with the requirements ASTM A53.

2.3 Catch pit and Grating

Catch pits and gratings shall be Gray Iron Casting with reliability test greater

than grade 50 as required by AASHTO A48 for heavy items, of the shape and

size and with the connection requirements as indicated on the drawings.

2.4 Fixing Brackets

The materials for fixing brackets shall conform to JIS G 3101, SS400, or equivalent standards and shall be galvanized or of other rust-resistance materials to the approval of the Engineer.

2.5 Submittals

The Contractor shall submit his method statement to the Engineer for his

approval. The method statement shall include but no be limited to

arrangements and details of pipes fittings and joints, means of casting the

catch pit into the structure and details of fixing pipe brackets to concrete

surfaces.

The Contractor shall submit to the Engineer for his approval manufacturer’s

certificates confirming that all materials meet the requirements of the relevant

standards and specifications. Certificates are required for pipes and all pipe

fittings and the catch pit and grating.

2.6 Delivery, Storage and Handling

Materials delivered to site shall be inspected for damage, unloaded, and stored

with the minimum handling. Materials shall be handled in such a manner as to

ensure delivery to storage or the point of installation in sound undamaged

condition. Pipes shall be carried and not dragged. Materials shall not be stored


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directly on the ground. The inside of pipes and fittings shall be kept free of

dirt and debris.

2.7 Installation

Drainage catch pits and gratings shall be installed complete at the locations

indicated on the drawings. Catch pits shall be cast into the structure or cast

into a previously formed box out as detailed in the Contractor’s method

statement. Where the catch pits are to be cast into a box out all relevant

details shall be subject to the approval of the Engineer. Where catch pits are

secured into box outs using concrete, the concrete shall be at least equal in

strength to the concrete in the surrounding structure and all box out faces

shall be prepared as required for construction joints. The inside faces of the

catch pit shall be painted in accordance with specification 08800 – Painting

table 1, system for aggressive conditions subject to the approval of the

Engineer.

All pipes and fittings shall be installed to the locations, lines and grades

indicated in the drawings. Cutting of pipe shall be avoided. Where pipes are

cut the cut end shall be cleaned and trimmed and painted in accordance with

specification 08800 – Painting immediately after cutting. All joints shall be

properly and securely made to ensure no leakage of water.

All pipe brackets shall be located and securely fixed in place before pipes are

installed.



3.1.1 Catch pits and gratings

Drainage catch pits, frames and gratings inclusive of all fittings shall be

measured for payment by the number of drainage sets of each type,

constructed and installed in accordance with the requirements of the drawings

and approved by the Engineer.

3.1.2 Drainage Pipe

Drainage piping shall be measured for payment by linear meters along the

centre and between intersections of the centre of the pipe for the steel drain

piping of the diameter and type required by the drawings. The measurement

by linear metre shall include all fixtures and fittings including pipe covers,

tees, pipe connectors, brackets and all necessary fitting, supports and

accessories indicated on the drawings or otherwise required. All rates shall

include protective coatings, and shall be for all items constructed, installed

and approved by the Engineer.

3.1.3 Basis of Payment

Payment shall be made in accordance with the applicable unit prices of the

pay items of the Bill of Quantities listed below, and shall include all labor,

equipment and incidentals necessary to install drainage catch pits, frames and

gratings and all piping and fittings.


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Pay Item Description Unit 07900-01 Pipe DN200 lm

07900-10 Catch Pit, frame and grating set No.


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spec concrete_07100 concrete

Documents

concrete mixing

concrete works2section

concrete classes83

concrete finishing233

concrete consistency193

concrete construction

concrete structures

finishing concrete surfaces233