1.0 GENERAL

1.1 Scope

1.1.1 This specification establishes the material specification of reinforced cement concrete to be used in pile foundation. Any special requirements as shown or noted on the drawings shall govern over the provisions of these specifications.

1.1.2 For specific work requirements concerning design and construction or otherwise modifying or supplementing the provision of this specification, refer to the specific requirements. In case of conflict between specific requirements and provision of this specification, former shall govern.

1.2 Definitions

1.2.1 Reference to Indian Standard Codes shall always mean reference to the latest issue of the relevant standards including all its amendments up to date.

1.3 Codes

All design and construction shall be performed in accordance with the Indian Standard Code of Practice for Plain and Reinforced Concrete I S:456.

2.0 MATERIALS FOR CONCRETE

All materials which may be used in the Plain or Reinforced Cement Concrete work shall be of Standard quality conforming to IS or equivalent and shall have IS certification mark as far as possible unless otherwise approved by the Engineer-in-Charge. The contractor shall get all materials approved by Engineer-in-Charge prior to its procurement and before actual use. The Engineer-in-Charge shall have the right to determine whether all or any of the materials offered or delivered for use in the works are acceptable. Any material brought to site and not conforming to specification and instruction of Engineer-in-Charge shall be rejected and the contractor shall have to remove the same immediately from site at his own expense.

2.1 Cement

2.1.1 General

The cement used shall be Portland slag cement conforming to IS: 455 latest version and the make of the same shall be approved by HPCL.

2.1.2 Tests after Delivery

Each consignment of cement may, after delivery on the site at the discretion of the Engineer-in-Charge, be subjected to any or all of tests and analysis required by the relevant Indian Standard Specifications. Facilities for testing shall be provided by contractor at his own cost.

2.1.3 Storage on the Site

The cement shall be stored in a suitable weather-tight building and in such a manner as to permit easy access for proper inspection to prevent deterioration due to moisture and to minimize warehouse deterioration. Cement of different type and brands shall be kept in separate storage. All accepted cement stored on the site shall be arranged in batches, and used in the same order as received from the manufacturer. The contractor shall maintain a cement register, in which all entries shall be completed day to day showing the quantities received, date of receipt, source of dispatch, type of cement, etc. and also the daily cement consumption on site. The register shall be accessible to the Engineer-in- Charge for his verification.

2.1.4 Rejection of Cement

The Engineer-in-Charge may reject any cement as a result of any tests thereof, notwithstanding the manufacturer’s certificate. He may also reject cement which has deteriorated owing to inadequate protection from moisture or due to intrusion of foreign matter or other causes. Any cement which is considered defective by the Engineer-in-Charge shall not be promptly removed from the site of the work by the contractor at his own expense.

2.2 Aggregates for Concrete

2.2.1 General

Coarse and fine aggregates for concrete shall conform in all respect to IS: 383, “Specification for Coarse and Fine Aggregates from Natural Sources for Concrete”. Aggregates shall be obtained from a source known to produce those satisfactory for concrete. Aggregates shall consist of naturally occurring sand and gravel or stone, crushed or uncrushed, or a combination thereof. They shall be chemically inert, hard, strong, dense, durable, clean and free from veins, adherent coatings and shall be of limited porosity. Flaky and elongated pieces shall not be used. The source of aggregates shall be approved by the Engineer-in-Charge and shall not be changed during the course of the job without his approval. Rejected aggregates shall be removed from the work site by the contractor at his own expense.

2.2.2 Deleterious Materials

Aggregates shall not contain any harmful materials such as iron pyrites, coal, mica, shale or similar laminated materials, clay, alkali, soft fragments, sea shells, organic impurities etc. in such quantities as to affect the strength or durability of the concrete. In addition to the above, for reinforced concrete, any material which might cause corrosion of the reinforcement and aggregates which are chemically reactive with the alkalis of cement shall not be used. The maximum quantities of deleterious materials in the aggregates, as determined in accordance with IS: 2386 (Part-II) “Methods of Test for Aggregates for Concrete”, shall not exceed the limits given in Table-I of IS: 383. The sum of the percentages of all deleterious materials shall not exceed five. Deleterious materials also include material passing 75 micron IS sieve.

2.2.3 Coarse Aggregates

Coarse aggregate is aggregate most of which is retained on 4.75 mm IS sieve. These may be obtained from crushed or uncrushed gravel or stone as per Cl. 2.3.1 and may be supplied as single sized or graded aggregates given in Table-II of IS: 383. The Engineer-in-Charge may allow all-in-Aggregate to be used provided they satisfy the requirements of clause 4.4 and T able-IV of IS 383.

2.2.4 Fine Aggregates

Fine aggregate is aggregate most of which passes 4.75 mm IS Sieve but not more than 10% pass through 150 microns IS Sieve. These shall comply with the requirements of grading zones I, II and III and given in Table-III of IS: 383. Fine aggregate conforming to grading zone IV shall not be normally used in reinforced concrete unless tests have been made by the contractor to ascertain the suitability of the proposed mix proportion and approved by the Engineer-in-Charge. Fine aggregate shall consist of natural sand resulting from natural disintegration of rock and which has been deposited by streams or glacial agencies, or crushed stone sand or crushed gravel sand.

2.2.5 Sampling and Testing

In case of doubt the Engineer-in-Charge may require the contractor to carry out tests, at the contractor’s expense in accordance with – IS: 516 – Method of Tests for Strengths of Concrete; and IS: 2386- Method of Tests for Aggregates for Concrete.

2.2.6 Storage of Aggregates

T he contractor shall at all times maintain at the site of work such quantities of aggregate as are considered by the Engineer-in-Charge to be sufficient to ensure continuity of work. Each type and grade of aggregate shall be stored separately on hard firm ground having sufficient slope to provide adequate drainage to rain water. Any aggregate delivered to site in a wet condition or becoming wet at site due to rain shall be kept in storage for at least 24 hrs. to obtain adequate drainage, before it is used for concreting, or the water content of mix must be suitably adjusted as directed by Engineer-in-Charge.

2.3 Water

Water used for concrete shall be clear and free from injurious amounts of Oil, Acid Alkali, Organic matters or other harmful substances in such amount that may impair the strength or durability of structure. Potable water shall generally be considered satisfactory for mixing and curing concrete. The Engineer-in-Charge may require the contractor to prove at latter’s expense, that the concrete mixed with water proposed to be used should not have a compressive strength, lower than 90% of the strength of concrete mixed with distilled water. The Engineer-in-Charge may require the contractor to get the water tested from an approved laboratory at his own expenses and in case the water contains any sugar or an excess of acid, alkali, any injurious salts, etc. the Engineer-in-Charge may refuse to permit its use.

3.0 Admixtures

3.1 Admixtures such as CICO grade I or KIM (KRYTON make) or equivalent may be used in concrete only with the approval of Engineer-in-Charge.

4.0 Reinforcement

4.1 HYSD Corrosion resistant Steel Bars

4.1.1 The reinforcement shall confirm to IS: 1786, Fe-415 grade. The reinforcement shall be Corrosion resistant steel and it shall be from SAIL/TISCO/RINL

4.2 Welding

4.2.1 Field welding of reinforcing bars will not be permitted without the written consent of the Engineer- in-Charge. Where welding is permitted it must be at staggered locations. Tests shall be made to provide that the joints are of the full strength of bars connected. Welding of reinforcement shall be done in accordance with the recommendation of IS: 2751.

4.3 Storage

4.3.1. The steel reinforcement shall be stored in such a way as to avoid distortion and to prevent deterioration and corrosion.

4.4 Other Specifications

4.4.1 General construction details and workmanship relative to reinforcement including bar bonds, lap splices and installation shall be in accordance with I S:2502- Code of Practice for Bonding and Fixing of Bars for concrete reinforcement, as well as the detailing of reinforcement given in I S:456.

4.4.2 Hot bending of bars shall not be allowed.

4.4.3 The number of sizes, shape and position of all the reinforcement shall, unless otherwise directed or authorized by the Engineer-in-Charge, be strictly in accordance with the drawings. The reinforcement shall be adequately secured and held in position by metal chairs and spacers. Ties of inter-sections shall be made with 16 SWG soft black annealed binding wire.

4.4.4 The contractor must obtain the approval of the Engineer-in-Charge for the reinforcement placed, before any concrete is placed in the forms. The reinforcement of this time shall be free from loose rust or scale or other coating that will destroy or reduce bond.

4.4.5 Concrete spacer blocks of the same strength as parent concrete shall be used to ensure correct cover to the reinforcement. This clear cover shall be as shown on the drawings or as per instructions of the Engineer-in-Charge.

4.4.6 All the reinforcing bars shall be so tied as to form a rigid cage to prevent displacement before or during concreting.