specification - reinforcement bars

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SPECIFICATION OF REINFORCEMENT BARSPROJECT MANAGEMENT-II

SUBMITTED BY:

SHISHUPAL SINGH

SPA/NS/BEM/526 School of Planning & Architecture, New Delhi

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SPECIFICATION OF REINFORCEMENT BARS

1. O REFERENCES o References to standards i) Is: 432 (Part I) 1982 Indian Standard Specification for Mild Steel and Medium Tensile Steel Bars and Hard-Drawn Steel Wire for Concrete Reinforcement. Part I: Mild Steel and Medium Tensile Steel Bars (Third Revision). ii) Is 8 432 (Part II) 1982 Indian Standard Specification for Mild Steel and Medium Tensile Steel Bars and hard-Drawn Steel Wire for Concrete Reinforcement. Part II Hard-Drawn Steel Wire (Third Revision). iii) IS: 1786-1979: Indian Standard Specification for Cold-Worked Steel High Strength Deformed Bars for Concrete Reinforcement. iv) IS: 1786-1966: Indian Standard Specification for Cold Twisted Steel Bars for Concrete Reinforcement. v) IS: 1566-1982: Indian Standard Specification for Hard Drawn Steel Wire Fabric for Concrete Reinforcement. vi) IS :1786-1985: (Superseding IS : 1139-1966) Indian Standard Specification for High Strength Deformed Steel Bars And Wires for Concrete Reinforcement. vii) IS : 5525 1969: Recommendations for detailing of Reinforcement in Reinforced Concrete works. viii) IS:2502-1999: Code of Practice for Bending and Fixing of Bars for Concrete Reinforcement. ix) IS: 9077-1979: Code of Practice for Corrosion Protection of Steel Reinforcement in Reinforced Brick and Reinforced Cement Concrete Construction x) IS: 10790(Part I):1984: Methods of Sampling of Steel for Pre-stressed and Reinforced Concrete xi) SP: 34 (S&T)-1987; Handbook on Concrete Reinforcement detailing xii) Commentary on CPWD Specifications: Cement Concrete Work

SHISHUPASL SINGH

M.B.E.M, SCHOOL OF PLANNING AND ARCHITECTURE

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SPECIFICATION OF REINFORCEMENT BARS

2.0

SCOPE OF WORK

The types of reinforcement bars included in the scope of the study are: Mild Steel Medium Tensile Steel Bars High Strength Deformed Steel Thermo-Mechanically Treated Bars Hard Drawn Steel Wires

2.1 The scope covers definitions of terms relating to concrete reinforcement. 2.2 The scope covers the requirements of mild steel and medium tensile steel plain bars in round and square sections for use as reinforcement in concrete. 2.3 The scope covers the requirements of hard-drawn steel wire of medium strength for use as reinforcement in concrete. 2.4 The scope covers the requirements for hard-drawn steel wire fabric consisting of harddrawn steel wire with cross wires electrically welded to them for use as concrete reinforcement. 2.5 The scope covers the requirements of deformed steel bars and wires for use as reinforcement in concrete, in the following three strength grades: Fe 415 Fe 500 Fe 550 2.6 The scope covers symbols and approximate dimensions of bends, and bending and fixing procedures for reinforcement. 2.7 The scope covers the general requirements of detailing of reinforcement in reinforced concrete structures. The recommendations may be applied to all reinforced concrete structures with suitable modifications as may be necessary. 2.8 The scope deals with the protection of reinforcement from corrosion in reinforced brick (RB) and reinforced cement concrete (RCC) construction.

SHISHUPASL SINGH

M.B.E.M, SCHOOL OF PLANNING AND ARCHITECTURE

4

SPECIFICATION OF REINFORCEMENT BARS

3.0 RELATED WORKS o Formwork

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The formwork shall be designed and constructed so as to remain sufficiently rigid during placing of reinforcement bars and concrete and compaction of concrete. ( IS 6461 : Part 5 : 1972) All rubbish, particularly chippings, shavings and saw dust shall be removed the interior of the forms. The face of the formwork in contact with the concrete shall be cleaned and treated with form release agent.( In the concrete construction industry, form release agents prevent the adhesion of freshly placed concrete to the forming surface, usually plywood, overlaid plywood, steel or aluminum). Form release agent should be applied so as to provide a thin uniform coating to the form without coating the reinforcement.

Conduiting o The conduiting of CI pipes for electrical shall be laid as per electrical layout drawings after the placing of reinforcement bars. o Nowhere should it be placed under the reinforcement bars as it may collapse under the load of the reinforcement.

Care should be taken not to displace the position of the conduits while working. o Concreting o The concrete shall be deposited as neatly as practicable in its final position to avoid rehandling. o There should not be displacement of any reinforcement or movement of formwork while placing concrete. o 4.0 GENERAL REQUIREMENTS o Submittal of shop drawings: Not relevant o Requirement of qualified staff: The contractor shall appoint well qualified staffs who would execute the work on site. The persons should have special expertise and skills to carry out the required work. o Requirement of tools and equipment: The required tools and equipment for carrying out the works shall be arranged by the contractor. The tools and plant shall be used to satisfy time, cost and quality parameters of work. o General handling, storage and protection requirementso Steel reinforcement stored at the work site shall be placed on platforms, skids, or other supports. This is done so that contact with the ground is avoided and the material is protected from mechanical damage and/or corrosion The space for storage of material shall be provided by the owner.M.B.E.M, SCHOOL OF PLANNING AND ARCHITECTURE

oSHISHUPASL SINGH

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SPECIFICATION OF REINFORCEMENT BARSo The steel reinforcement shall be stored by the contractor at site of work in such a way as to prevent distortion and corrosion and nothing extra shall be paid on this account. Bars of different sizes and lengths shall be stored separately to facilitate easy counting and checking. Contractor shall make arrangements for the protection of the materials.

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o Environmental requirements:o o Lighting levels shall be maintained at the work place. If natural light is no accessible, then artificial lighting shall be provided at no extra cost by the contractor to ensure quality of work

5.0 MATERIALS o Material data: MILD STEEL AND MEDIUM TENSILE STEEL BARS oo o o o o Mild steel bars Medium tensile steel bars 5.1.2 Mild steel bars shall be supplied in the following two grades: Mild steel bars, Grade I designated as Fe 410-S Mild steel bars, Grade II designated as Fe 410-O Medium steel bars, Grade II designated as Fe 540-W-HT Sizes: Mild steel and medium tensile steel bars shall be supplied in the following nominal sizes: Diameter of round bars or side 5, 6, 8, 10, 12, 16, 20, 22, 25, 28, of square bars: 32, 36, 40, 45 and 50 mm Mass the mass of bars shall be in accordance with IS: 1732-1971-f. 5.1.4 Tolerances: The rolling and cutting tolerances shall be in accordance with IS: 1852-1973, IS: 1786 Tolerance on nominal mass Percent Batch Individual Individual sample + sample for coil (-x-) +7 +8 +8 5.1.3 Reinforcement supplied in accordance with this standard shall be classified into the following types:

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Nominal size in mm

5.1.5

Upto and including 10 Over 10, upto +5 -6 +6 and including 16 Over 16 +3 -4 +4 Physical requirements: The ultimate tensile stress and percentage elongation is determined according to the following table:

SHISHUPASL SINGH

M.B.E.M, SCHOOL OF PLANNING AND ARCHITECTURE

6

SPECIFICATION OF REINFORCEMENT BARS

S.No

Type and nominal size of bar (min) Mild Steel Grade IFor bars up to and including 20 mm For bars over 20 mm, up to and including 50 mm

Ultimate tensile stress (min) 410 410

Yield stress (min)

Elongation Percentage (min) 23 23

1

250 240

2

Mild Steel Grade IIFor bars up to and including 20 m For bars over 20 mm, up to and including 50 mm

370 370

225 215

23 23

3

Medium Tensile SteelFor bars up to and including 16 mm For bars over 16 mm, up to and including 32 mm For bars over 32 mm, up to and Including 50 mm

540 540 510

350 340 330

20 20 20

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Handling, storage and protection5.2.1 Every care should be taken to avoid mixing different types of grades of bars in the same structural members as main reinforcement to satisfy relevant clause of IS: 456. In case of structures, wherever the situation necessitates, the change over shall be made only room any one level onwards. In case of foundations, all foundation elements (footings ring beams, piles and pile caps) shall have the same kind of steel. In the case of columns, all structural elements up to the level of change, where the changeover is taking place should have the same kind of steel as those in columns 5.2.1 The reinforcing steel brought to site of work shall be stored on brick / timber pedestal height, nothing extra shall be paid on this account. 5.2.2 All finished bars shall be well and cleanly rolled to the dimensions and weights specified. They shall be free from cracks, surface flaws, laminations and rough, jagged and imperfect edges and all other harmful defects. 5.2.3 Transporting Reinforcement: Reinforcement shall be transported to the site of work or to the place of storage by such means and in such a manner that the reinforcement is neither damaged nor deformed. The unloading of the reinforcement shall be done at the nearest convenient place where it is to be processed further. Particularly in cases where unloading is required to be done by hand, it is important that the vehicle should be brought as close as possible to the stacking or bending place in order to avoid carryi

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