Download - Specification - Reinforcement Bars

SPECIFICATION OF REINFORCEMENT BARS

PROJECT MANAGEMENT-II

SUBMITTED BY:

SHISHUPAL SINGHSPA/NS/BEM/526

School of Planning & Architecture, New Delhi

2 SPECIFICATION OF REINFORCEMENT BARS

1. O REFERENCES

o References to standardsi) 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


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 hard-drawn 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.



3.0 RELATED WORKS

o Formwork

o 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)

o All rubbish, particularly chippings, shavings and saw dust shall be removed the interior of the forms.

o 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).

o Form release agent should be applied so as to provide a thin uniform coating to the form without coating the reinforcement.

o 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.

o 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.

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 requirements

o 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

o The space for storage of material shall be provided by the owner.

o 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.

o Contractor shall make arrangements for the protection of the materials.

o Environmental requirements:

o Lighting levels shall be maintained at the work place.

o 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

o Reinforcement supplied in accordance with this standard shall be classified into the following types:

o Mild steel bars

o Medium tensile steel bars

5.1.2 Mild steel bars shall be supplied in the following two grades:

o Mild steel bars, Grade I designated as Fe 410-S

o Mild steel bars, Grade II designated as Fe 410-O

o Medium steel bars, Grade II designated as Fe 540-W-HT

5.1.3 Sizes: Mild steel and medium tensile steel bars shall be supplied inthe following nominal sizes:

o 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

o 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

Nominal size in mm

Batch Individual sample +

Individual sample for coil

(-x-)

Upto and including 10

+7 +8 +8

Over 10, upto and including 16

+5 -6 +6

Over 16 +3 -4 +4

5.1.5 Physical requirements: The ultimate tensile stress and percentage elongation is determined according to the following table:

S.No Type and nominal size of bar

(min)

Ultimate tensile stress

(min)

Yield stress

(min)

Elongation

Percentage

(min)

1 Mild Steel Grade IFor bars up to and including 20 mmFor bars over 20 mm, up to and including 50 mm

410

410

250

240

23

23

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 Steel

For 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

o Handling, storage and protection

5.2.1 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 carrying over long distances. As far as possible, at the time of unloading the bars should be separated by sizes and lengths.

5.2.4 Storage of Reinforcement: The actual location of the stacking place of reinforcement depends upon the site conditions, but it should be such that the reinforcement could be conveniently received and supplied to the operational centers in the site. On works covering large area;, it might be an advantage to stack the reinforcement at different places close to the areas where they are likely to be used most.In order to ensure that the reinforcement bars are kept in good condition, they should not be left in direct contact with the ground but they should be stacked on top of an arrangement of timber sleepers or the like. Suitable racks may also be used for stacking reinforcement in tiers. Where space is extremely limited, bars may also be stacked vertically but the vertical stacking has the disadvantage that it is more difficult to get the bars in and out and in identifying bars of different sizes and lengths. Whatever method of stacking is adopted, the bars should be stacked in such a way that the various sizes and lengths can be quickly and easily identified. After the reinforcement bars have been bent, they should be placed in the most convenient locations for transport.Flexible bends like stirrups and bends of small 8” diameter bars should be grouped together and bundled for ease of handling. Each bundle of bars or group of bars should have labels affixed to it indicating the bar mark, bending schedule reference number and its position in laying. In storing bars, attention shall be paid to avoiding distortion and to preventing deterioration and corrosion. Whilst a certain amount of hard rust on the reinforcement is considered desirable in reinforced concrete work, care should be taken to ensure that undue rusting or loose scaling do not take place in storage and in such conditions of weather where the reinforcement is likely to get corroded, the stack of reinforcement shall be suitably sheltered.

5.2 Quality Assurance5.2.1 Submittal of Manufacturer’s/Supplier’s test documents:

5.2.1.1 Unless otherwise specified, general requirements relating to the supply of

material, inspection and testing shall conform to IS: 1387-1967.

5.2.1.2 No material shall be dispatched from the manufacturer's or suppliers'

premises prior to its being certified by the purchaser or his authorized



representative as having fulfilled the tests and requirements laid down in

this standard except where the bundle or coil containing the bars is

marked with the ISI Certification Mark.

5.2.1.3 The purchaser or his authorized representative shall be at liberty to

inspect and verify the steel maker's certificate of cast analysis at the

premises of the manufacturer or supplier; when the purchaser requires an

actual analysis of finished material, this shall be made at a place agreed

to between the purchaser and the manufacturer or supplier.

5.2.1.4 Manufacturer's Certificate: In the case of bars which have not been

inspected at the manufacturer's works, the manufacturer or supplier, as

the case may be, shall supply the purchaser or his authorized

representative with the certificate stating the process of manufacture and

also the test sheet signed by the manufacturer giving the result of each

mechanical test applicable to the material purchased, and the chemical

composition, if required. Each test sheet shall indicate the number or

identification mark of the cast to which it applies, corresponding to the

number or identification mark to be found on the material.

5.2.1.5 Identification and Marking:

o The manufacturer or supplier shall have ingots, billets and bars or bundles

of bars marked in such a way that all finished bars can be trace to the cast

from which they were made. Every facility shall be given to the purchaser or

his authorized representative for tracing the bars to the cast from which they

were made.

o The medium tensile steel bars shall be suitably marked to identify them from

mild steel bars. Mild steel bars Grade I and II shall have distinctive

identification tags.

o Each bundle or coil containing the bars may also be suitably marked with the

Standard Mark, in which case the concerned test certificate shall also bear the

Standard Mark.

5.2.2 Independent Laboratory Test

5.2.2.1 Selection and Preparation of Test Samples: Unless otherwise specified

in standard, the requirements of IS: 226-1675 shall apply.

5.2.2.2 All test pieces of bars shall be selected by the purchaser or his

authorized representative, either:

a) From the cutting of bars

b) From any bar or the coil, after it has been cut to the required or

specified length and the test piece taken from any part of it



c) In neither case, the test piece shall be detached from the bar or the

coil, except in the presence of the purchaser or his authorized

representative.

d) Before test pieces are selected, the manufacturer or supplier shall

furnish the purchaser or his authorized representative with copies of

the mill records giving the number of bars in each cast with sizes as

well as the identification marks whereby the bars from their cast or

each coil can be identified.

5.2.2.3 Tensile Test: The ultimate tensile stress, yield stress and elongation of

bars shall be determined in accordance with the requirements of

IS: L608-1972 read in conjunction with IS: 226-1975. The test

pieces shall be cut from the finished material and straightened where

necessary. They shall not be annealed or otherwise subjected to heat

treatment. Any slight straightening which may be required shall be done

cold. In case of bars, the size of which is net uniform throughout the

length of test piece, limit is shall be applied according to the actual maxi-

mum thickness of the piece selected for testing. Should a tensile test

piece break ontside the middle half of its gauge length and the percentage

elongation obtained is less than that specified, the test may be discarded

at the manufacturer's option, and another test made from the same bar.

5.2.2.4 Bend Test: The bend test shall be performed in accordance with the

requirements of IS: 1599-1974 read in conjunction with IS: 226-1975.

5.2.2.5 Retest: (As per IS: 1786) Should any one of the test pieces first selected

fail to pass any of the tests specified in this standard, two further samples

shall be selected for testing in respect of each failure. Should the test

pieces from both these additional samples pass, the material represented

by the test samples shall be deemed to comply with the requirements of

that particular test. Should the test piece from either of these additional

samples fail, the material represented by the test samples shall be

considered as not having complied with this standard.

5.2.3 Sampling: Sampling for tensile and bend tests shall be in accordance with

IS: 226-1975.

5.3 Material data: HIGH STRENGTH DEFORMED STEEL BARS AND WIRES FOR CONCRETE REINFORCEMENT

5.3.1 Chemical Composition: The ladle analysis of steel when made as per

relevant parts of IS : 228 shall be as follows:



Constituents Percent, Maximum

Fe 415 Fe 500 Fe 550

Carbon0.30 0.30 0.30

Sulphur 0.06 0.55 0.55

Phosphorus 0.06 0.55 0.55

Sulphur and

phosphorus0.11 0.105 0.10

5.4.2 The nominal sizes of bars/wires shall be as follows:

‘Nominal size, 4, 5, 6, 7, 8, 10, 12, 16, 18, 20, 22, 25, 28, 32, 36, 40, 45 and 50

mm’.

Other sizes may also be supplied by mutual agreement.

5.3.2 Deformations and Surface Characteristics: For high strength deformed

bars/wires, the mean area of ribs (in mm2 ) per unit length (in mm ) above the

core of the bar/wire, projected on a plane normal to the axis of the bar/wire

calculated in but shall not be less than the following values:

5.3.3 Tolerances on Dimensions and Nominal Mass:

5.3.3.1 Specified Lengths: if bars/wires are specified to be cut to certain

lengths, each bar/wire shall be cut within deviations of 1 JS mm on the

specified length, but if minimum lengths are specified, the deviations

shall be +50 mm and —0 mm.

5.3.3.2 Nominal Mass: For the purpose of checking the nominal mass, the

density of steel shall be taken as 0.007 85 kg/mm2 of the cross-sectional

area per meter run. Unless otherwise agreed to between the manufacturer

and the purchaser, the tolerances on nominal mass shall be as in Table.

Tolerance on nominal mass Percent

Nominal size in mm

Batch Individual sample +

Individual sample for coil

(-x-)

Up to and including 10

+7 -8 +8



Over 10, up to and including 16

+5 -6 +6

Over 16 +3 -4 +4

5.3.3.3 Physical Properties: Proof stress, percentage elongation and tensile

strength for all sizes of deformed bars/wires determined on effective

cross-sectional area shall be as specified in Table.S.No.

Property Grade

Fe415 Fe500 Fe550

i0.2 percent proof yield stress, Min, stress/ N/mm2

415 500 550

ii Elongation, percent, Min, on gauge length 5*65 VA, where A is the cross-sectional area of the test piece

14.5 12.0 8.0

iii Tensile strength, Min

10 percent more than the actual 0'2 percent proof stress but not less than 4850 N/mm4

8 percent more than the actual 0.2 percent proof stress but not less than 545-0 N/mm'

6 percent more than the actual 0.2 percent proof stress but not less than 585-0 N/mm1

5.4 Handling, storage and protection

5.4.1 As clause 5.2

5.5 Quality Assurance

5.5.1 As clause 5.3


5.5.2.1 Selection and Preparation of Test Sample: Unless otherwise specified

in this standard, the requirements of IS: 226-1975 shall apply.

5.5.2.2 All test pieces of bars shall be selected by the purchaser or his

authorized representative, either:

a) From the cutting of bars

b) From any bar or the coil, after it has been cut to the required or

specified length and the test piece taken from any part of it



c) In neither case, the test piece shall be detached from the bar or the

coil, except in the presence of the purchaser or his authorized

representative.

d) Before test pieces are selected, the manufacturer or supplier shall

furnish the purchaser or his authorized representative with copies of

the mill records giving the number of bars in each cast with sizes as

well as the identification marks whereby the bars from their cast or

each coil can be identified.

e) In neither case, the test piece shall be detached from the bar/wire

except in the presence of the purchaser or his authorized

representative.

f) The test pieces obtained shall be full

sections of the bars/wires and shall be subjected to physical tests

without any further modifications. No reduction in size by

machining or other wise shall be permissible, except in case of bars

of size 0.28 mm and above.

g) No test piece shall be annealed or otherwise subjected to

heat treatment. Any straightening which a test piece may require

shall be done cold.

h) For the purpose of carrying out tests for tensile strength, proof stress

and percentage elongation for bars 28 mm in diameter and above,

deformations of the bars only may be machined. For such bars, the

physical properties shall be calculated using the actual area obtained

after machining.

i) Notwithstanding the provisions, test pieces may be subjected to

artificial ageing at a temperature not exceeding 100°C and for a

period not exceeding 2 hours.

5.6.2.3 Tensile Test: The tensile strength, 0.2 percent proof stress and

percentage elongation of bars/wires shall be determined in accordance

with requirements of IS: 1608-1972 read in conjunction with IS: 226-

1975. Alternatively and by agreement between the purchaser and the

supplier, for routine testing, the proof stress may be determined in con

junction with the tensile strength test and may be taken as the stress

measured on the specimen whilst under load corresponding to an in

crease measured by an extensometer of 0.4 percent for Fe 415

bars/wires, 0.45 percent for grade Fe 500 bars/wires and 0.47 percent for



grade Fe 550 bars/wires the total strain on any convenient gauge length.

The stresses shall be calculated using the effective cross-sectional area of

the bar/wire.

5.6.2.4 Bend Test: The bend test shall be performed in accordance with the

requirements of IS: 1599-1974 and the mandrel diameter shall be as

specified in Table. The specimen shall be considered to have passed the

test if there is no transverse crack in the bent portion.

MANDREL DIAMETER FOR’ DIFFERENT GRADES

Up to and over 22

Fe 415 Fe 500 Fe 550

3Ø 4Ø 5Ø

4Ø 5Ø 6Ø

5.6.2.5 Rebend Test: The test piece shall be bent to an included angle of 135°

using a mandrel of appropriate diameter. The bent piece shall be aged by

keeping in boiling water (100°C) for 30 minutes and then allowed to

cool. The' piece shall then be bent back to have an included angle of

157°. The specimen shall be considered to have passed the test if there is

no fracture in the bent portion

Nominal Size of

Specimen

Dia of Mandrel for Fe 415 and

Fe 500

Dia of Mandrel for Fe 550

Up to and including 10 mm and over 10 mm

5Ø 7Ø

7Ø 8Ø

Where = is the nominal size in mm of the test piece.

5.6.2.6 Retest: (As per IS: 1786) Should any one of the test pieces first selected

fail to pass any of the tests specified in this standard, two further samples

shall be selected for testing in respect of each failure. Should the test

pieces from both these additional samples pass, the material represented

by the test samples shall be deemed to comply with the requirements of

that particular test. Should the test piece from either of these additional

samples fail, the material represented by the test samples shall be

considered as not having complied with this standard.



5.6.2.7 Selection of Test Specimens: For checking nominal mass, tensile

strength, bend test and rebend test, test specimen of sufficient length

shall be cut from each size of the finished bar/wire at random at a

frequency not less than that specified in Table.

Nominal size Quantity

For casts/heats

below 100 tones

For casts/heats over

100 tones

Under 10 mm 1 sample from each 25

tones or part thereof

1 sample from each 40 tones or part thereof

10 mm to 16 mm (inclusive) 1 sample from each 35


1 sample from each 45 tonnes or part thereof

Over I6 mm 1 sample from each 45


1 sample from each 50 tonnes or part thereof

Bond Test — The frequency of bond test as required shall be as agreed to between the manufacturer and the purchaser/testing authority.

5.6.3 Sampling: Sampling for tensile and bend tests shall be in accordance with

IS: 226-1975

5.7 Material data: THERMO-MECHANICALLY TREATED BARS

5.7.2 Chemical composition

Carbon 0.30% (max)

Sulphur 0.06% (max)

Phosphorus 0.06% (max)

S & P 0.11% (max)

Silicon 0.10% (max)

5.7.3 Grade: Shall be of strength Fe 415 and Fe 500

5.7.4 Nominal size: 8, 10, 28, 32, 36

5.7.5 Nominal weight (kg/m): 8, 10, 28, 32, 36

5.7.6 Tolerance: As per that of High Strength Deformed Steel Bars

5.7.7 Physical properties:

Properties Fe 415 Fe 500

Yield strength (mpa) min 415 500

Tensile strength (mpa) min 485 545

Elongation (%) min 14.5 12


5.8.2 As clause 5.2




5.9.2 As clause 5.3

5.9.3 Independent Laboratory Test: Tests shall be carried out as per IS: 1786-1985

5.9.3.6 Tensile test: As per clause 5.6.2.3

5.9.3.7 Bend test: As per clause 5.6.2.4

5.9.3.8 Rebend test: As per clause 5.6.2.5

5.9.3.9 Retest: As per clause 5.6.2.6

5.9.4 Sampling: As per clause 5.6.3

5.10 Material data: HARD-DRAWN STEEL WIRE FABRIC FOR CONCRETE REINFORCEMENT5.10.1 Chemical Composition: The wire shall be cold drawn from mild steel made by

the open hearth, electric duplex, acid Bessemer, basic oxygen or a combination

of this process. In case any other process is employed in the manufacture of the

steel prior approval is required from the purchaser should be obtained. In case

basic oxygen process is employed for manufacture, the basic nitrogen content

shall not exceed to 0.008%.

The ladle analysis when made in accordance with relevant parts of IS: 228 shall

show that steel contains not more than 0.05% of sulphur and not more than 0.05%

of phosphorus.

Butt joints in the wires of the fabric shall be electrically welded and the joints

shall be staggered.

5.10.2 Nominal size (Sizes of Sheets or Rolls): The hard drawn steel wire are provided

in following sizes 2.65, 3.0, 3.15, 3.55, 4.0, 4.5, 4.75, 5.0, 5.3, 5.6, 6.0, 6.3, 7.1,

7.5, 8.0, 9.0, 9.5 and 10 mm.

Mesh sizes, weight and sizes of wires for square and oblong welded wire fabric

shall be as agreed to between the purchaser and the manufacturer.

5.10.3 Tolerance on Size of Sheet: When fabric is required to be cut to specified

dimensions, the tolerance shall be as follows:

For dimensions of 5 mm and under: 25 mm under or over the specified dimension

For dimensions over 5 mm: ½ percent under or over the specified dimension

5.10.4 Tolerance on Mass of Fabric: The tolerances on the mass of fabric shall be as

follows:



When the specified mass is not stated to be

either a maximum or a minimum: ± 6 percent

When the specified mass is stated

to be a maximum: 0-12 percent

When the specified mass is stated

to be a minimum: 12-0 percent

5.10.5 Mass: The nominal mass of fabric shall be calculated on the basis that steel

weighs 0.785 kg/cm² of nominal cross-sectional area per meter run.

The actual mass of the fabric shall be determined by weighing a sheet or sheets

of any convenient size, and if possible at least one square meter, with the edges

trimmed so that the longitudinal wires protrude by a distance equal to half the

distance between the cross wires, and the cross wires produce a distance equal to

half the distance between the longitudinal wires.

5.10.6 Physical properties: All wires of the finished fabric shall meet the minimum requirements for physical properties as prescribed in IS : 432 (Part II)-1982 except elongation.


5.11.1 As clause 5.2


5.12.1 As clause 5.3


a) All test pieces of bars shall be selected by the purchaser or his authorized

representative, either: All test pieces shall be selected by the purchaser, and

in the event of the tests being satisfactory, he shall pay the cost of the sheets

from which the test pieces have been cut, or accept delivery as though such

test pieces had not been cut there from.

b) The test pieces for tensile and bend tests shall be so cut from the fabric that

each tensile test piece shall contain one or more cross welds in its length.

c) Identification of Specimens with the Materials: The manufacturer shall make

appropriate arrangements for the identification of the material represented by

the test pieces.



5.12.2.1 Tensile Test: The tensile test shall be made on the mesh after

fabrication across one or more welds to the requirements specified in IS:

1521-1972. One tensile test shall be made from every 6 000 m² of fabric.

5.12.2.2 Bend Test: The bend test shall be made on the test pieces cut from

the longitudinal wire as well as the transverse wire, between the welds.

The test piece shall not be annealed or subjected to any heat treatment

before testing. The test piece shall withstand one complete cycle of

reverse bend around a pin of size indicated below, without showing any

signs of fracture when reverse bend test is carried out in accordance with

the requirements of IS : 1716-1971. One reverse bend test shall be made

from every 6 000 m² of fabric.

5.12.2.3 Retest: (As per IS: 1786) Should any one of the test pieces first

selected fail to pass any of the tests specified in this standard, two

further samples shall be selected for testing in respect of each

failure. Should the test pieces from both these additional samples

pass, the material represented by the test samples shall be deemed

to comply with the requirements of that particular test. Should the

test piece from either of these additional samples fail, the material

represented by the test samples shall be considered as not having

complied with this standard.

5.12.3 Delivery, Inspection and Testing Facilities

5.12.3.1 Delivery

All fabric reinforcement shall be delivered free from oil and grease, paint,

loose mill scale, loose rust and other matter likely to adversely affect the

bend with concrete.

Lime wash shall be permitted unless otherwise specified by the purchaser.

A sheet shall not contain any broken wires, and no broken cross welds in

excess of four percent of the total number of welded joints, or half of the

welded joints in any wire.

If so required by the purchaser, the manufacturer shall give a certificate that

the welded wire mesh supplied conforms in all respects to the requirements

of this specification.

If so required by the purchaser, the manufacturer shall give a certificate that

all welded intersections of the welded wire mesh supplied shall be capable of

withstanding a load in shear of not less than one quarter of that necessary to



develop the load, calculated from the specified proof stress in tension of the

smaller of the intersecting wires.

If required by the purchaser, this test shall be performed according to mutual

agreement between the purchaser and the manufacturer.

The purchaser or his authorized representative shall be at liberty to inspect

and verify the steel maker’s certificate of cast analysis at the premises of the

manufacturer or supplier; when the purchaser requires an actual analysis of

finished material, this shall be made at a place agreed to between the

purchaser and the manufacturer or the supplier.

The purchaser shall have all reasonable facilities for satisfying himself that

the material is being or has been manufactured fully in accordance with the

requirements of this specification and, for this purpose he shall be furnished

with the test certificates giving the results of test specified in this

specification and he shall have free access to the relevant parts of the

supplier’s works at all reasonable times as agreed to mutually. He shall be at

liberty to inspect the manufacture without interfering in any way with the

normal production of the material at any stage and to reject any material

which does not conform to this specification.

If so required by the purchaser, he shall be informed by the supplier when the

material relating to the order is under manufacture.

The supplier shall supply labor and appliances required for testing at his

premises. If facilities are not available at his own works, the supplier shall

bear the cost of the tests carried out in a laboratory selected by the purchaser.

5.12.4 Independent Test

Should there be a dispute about the compliance of the material with this

specification, the supplier and the purchaser each shall have the right to get

the material tested by a mutually acceptable independent testing authority

unless such disputes are within the terms of any other agreement for

reference or submission to arbitration

The results obtained by the independent testing authority shall be accepted as

final. If the material does not comply with this specification, the cost of

independent testing shall be borne by the supplier; if the material complies

with this specification, the cost shall be borne by the purchaser.

5.12.5 Defects Revealed After Delivery



Should any material after delivery be found not to be in accordance with this

specification, such material shall be deemed not to comply with this Indian

Standard not withstanding any previous acceptance, provided it has not been

improperly treated.

6.0 PROCESS STAGES

6.1 Cutting

o The reinforcement shall be cut in accordance with the cutting schedule.

o Cutting should be made with the aid of shear power operated or care should be taken not to damage the ribs in the neighborhood of the shear section.

o The cutting tolerance is as mentioned in the table

Dimension (cm) Tolerance (mm)

For bent bars < 75 +3

> 75 < 150 +5

> 150 < 250 +5

> 250 -10

+6

-15

+7

-25

For straight bars All lengths +25

-25

o The cut lengths should be measured on a measuring table to ensure flatness and straightness of the bars.

6.2 Fabrication



o Fabrication should be carried out in accordance with the bar bending schedule.o Plain smooth surfaces or rolls that do not offer resistance to longitudinal

movement to the bars or fabric being shall be provided to ensure adequate support.

o Over all dimensions of the fabricated reinforcement shall conform to the plan.

o The fabricator shall ensure that cutting and bending machine operatives are trained in the skills necessary to produce cut and bent products of consistent quality within the permissible size deviations. A formal operative approval and testing system shall be implemented and operatives shall have been certified by the fabricator as having achieved minimum standards of competence.

6.3 Assembly of Reinforcement

o Reinforcements shall be bent and fixed in accordance with procedure specified in IS: 2502.

o The high strength deformed bars should not be re-bent or straightened with the approval of Engineer-in-charge.

o Bar bending schedules shall be prepared for all reinforcement work.o All reinforcement shall be placed and maintained in the position shown in

respective drawings by providing proper cover blocks, spacers, supporting bars etc.

o Crossing bars should not be tack-welded for assembly of reinforcement unless permitted by Engineer-in-charge

6.4 Placing of Reinforcements

o Rough handling, shock loading (prior to embedment) and dropping of reinforcement from a height should be avoided.

o Reinforcement should secured against displacement outside the specified limits.o Reinforcement should be placed and tied in such a way that concrete placement

be possible without segregation of the mix.o Within the concrete mass, different types of metal in contact should be avoided to

ensure that bimetal corrosion does not take place

6.5 Tolerance on Placing of Reinforcement

Unless otherwise specified by the Engineer-in-charge the reinforcement shall be placed within the following tolerances:For effective depth 200mm or less +10mmFor effective depth more than 200mm +15mm

6.6 Reinforcement Spicing/Overlapping Reinforcements

o Where splices are provided in the reinforcing bars, they shall as far as possible be away from sections of maximum stress and staggered.



o It is recommended that splices in flexural members should not be at sections where bending moment is more than 50% of the moment of resistance; and not more than half the bars shall be spliced at a section.

o Where more than one half of the bars are spliced at a section or where splices are made at points of maximum stress, special precautions shall be taken, such as increasing the length of lap and/or using spirals or closely spaced stirrups around the length of splice

6.6 Lap Splices

o Lap splices shall not be used for bars larger than 36mmfor larger diameters, bar may be welded.

o In cases where welding is not practicable, lapping of bars larger than 36mm may be permitted, in which case additional spiral should be provided around the

lapped area.o Lap splices shall be considered as staggered if the center to center distance of the

splices is not less than 1.3 times the lap length calculated.o Lap length including anchorage value of hooks for bars in flexural tension shall

be Ld (Development Length) or 30Ø whichever is greater and for direct tension shall be 2Ld or 30Ø whichever is greater. The straight length of the lap shall not be less than 15Ø or 200mm.

o The lap length in compression shall be equal to the development length in compression calculated but not less than 24Ø

o When two bars of two different diameters are to be spliced the lap length shall be calculated on the basis of the diameter of the smaller bar.

o When splicing of welded wire fabric is to be carried out, lap splices of wires shall be made so that overlap measured between the cross wires shall be not less than the splicing of cross wires plus 100mm.

o In case of bundled bars, lapped splices of bundled bars shall be made by splicing one at a time; such individual splices within a bundle shall be staggered.

6.7 Bending of bars

o Bars shall be bent cold o Bars larger than 25mm in size may be bent hot at cherry red heat (not exceeding

8500C except those bars which depend for their strength on cold-working. Hot bars shall not be cooled by quenching.

o Bending of bars shall be done either by improvised means or by hand-operated machines and power operated benders.

6.8 Tying of bars

o Bars crossing each other, where required, shall be secured by binding wire (annealed) of size not less than 0.90 mm and conforming to IS: 280-1962 Specification for Mild Steel Wire (Revised), in such a manner that they will not slip over each other at the time of fixing and concreting.

o Every compression bar shall be tied at least in two perpendicular directions.o Stirrups may be staggered, provided it is ensured that the corresponding stirrups

form a uniform pattern in elevation.



6.8 Cover blocks

o Cover blocks, which are generally of cement mortar, shall be use& to ensure the required cover for reinforcement.

o Cover blocks are generally square or rectangular in plan with or without binding wire embedded in them which will be tied to the reinforcement at the time of placing.

o Kings with suitable hole at the centre may also be used.o The mortar or concrete used for the cover blocks or rings shall not be leaner than

the mortar or concrete in which they will be embedded.o To provide necessary cover for reinforcement at any section, only single cover

blocks shall be used.

6.8 Slabs, Beams and Columns

o Slabs: In slabs, whether double or multiple, layers of reinforcement are provided, the distances between the layers may be maintained

o Beams: In beams with top reinforcement, it is desirable to suspend the top reinforcement from the formwork by suitable arrangements which may be removed on completion of concreting up to the appropriate level, unless such reinforcement is otherwise rigidly held in position by stirrups or other members.

o Column Reinforcement: The column reinforcement, especially in heavily reinforced columns and in columns subjected to a combination of direct load and bending, should be properly tied; otherwise the strength of the column will be considerably affected. The ties may. Be staggered provided it is ensured that the corresponding ties form a uniform pattern in elevation and they shall be in closed loops. Distortion of projecting vertical bars in double rows in walls may be prevented prior to completed assembly of horizontal reinforcement and erection of shutters by the arrangements. This arrangement consists of a longitudinal timber or large bar placed along each row of vertical bar and tied to each bar. Between every sixth bars of opposite rows a cross piece of wood or steel should be tied.For single vertical row of large bars in walls, a timber frame may be employed to prevent the distortion of bar. The dimensions, details and spacing of the frame shall be determined by the nature of the work.

7.0 QUALITY CONTROL

7.1 Fabricator’s inspection: the fabricator shall carry out the following parameters of the schedules and of specimens of cut lengths and bent items at a frequency given below:

7.1.1 Cut Lengths

o The bar or fabric marko The type and size of the specimen and the type and size given on the schedule

o The length of the specimens and the length given on the schedule



7.1.2 Bent items

o The bar or fabric marko The type and size of the specimens and the type and size given on the schedule

o The diameter of the former used (by checking the bar)

o The shape of the specimens and the shape code given on the schedule.

7.1.3 Frequency

o The fabricator shall inspect daily and inspection records shall be retained for 10 years. Specimens shall be selected at random from a representative range of output items at the following frequency:

Where the output of the fabrication unit over the preceding full working week is less than 75t

At least 10 specimens per day

Where the output of the fabrication unit over the preceding full working week is between 75t and 150t


Where the output of the fabrication unit over the preceding full working week is greater than 150t


o Where no records are available covering the preceding full working week, the lesser of either 40 specimens per day or total output per day shall be inspected.

o For inspection purposes, not more than 50% of the specimen shall be selected from items having an identical bar mark. If any specimen that are inspected are found to have parameters that do not comply with the appropriate requirements all the other bars and fabrics with the same mark (or numbers), shall be inspected and they shall all comply with the appropriate requirements.

7.1.4 Inspection: All material shall be subject to routine inspection and testing by the manufacturer or supplier in accordance with this standard and a record of the test results of material conforming to this standard shall be kept by the manufacturer or the supplier. The records shall be available for inspection by the purchaser or his representative. In the case of material delivered to a supplier, the manufacturer shall supply a certificate containing the results of all the required tests on samples taken from the delivered material.

8.0 MEASUREMENT

8.1 Reinforcement: Unless otherwise stated reinforcement shall be measured separately. Where concrete and reinforcement are measured as a composite item they shall be fully described



indicating that supply of reinforcement is included in the item; in such cases items identical in other respects but varying in reinforcement shall be measured separately.o Reinforcement bars shall be measured in running meters. o The item of work shall include removal of surface rust, straightening, cutting to lengths,

hooked ends, cranking or bending (straight or spiral). Authorized overlaps, chairs/separators shall be measured.

o When welding of joints is authorized the same shall be described; joints, butt welded shall be measured in numbers and lap welded shall be measured in running meters of the length welded.

o Fabric reinforcement shall be described (including meshes and strands) and measured in square meters. Authorized laps shall be measured.

o Wire netting used as encasement shall be described (including meshes and wires) and shall be measured in square meters. Authorized laps shall be measured.

o Raking or circular cutting and waste shall be included in description.o Binding wire for reinforcement shall not be measured, but shall be included in description of

item.


Download - Specification - Reinforcement Bars

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