METHODOLOGY / PROCEDURE OF REINFORCEMENT BAR CUTTING, BENDING & FIXING

WORK METHODOLOGY  OF REINFORCEMENT BAR CUTTING, BENDING & FIXING

As per  IS : 2502 & IS : 456

 

Step – 1 : Delivery and Storage of Reinforcement bars

              

            Fig. Steel Stacking Yard

Ø  Reinforcement bars shall be stacked above the ground minimum of 200 to 300 mm in clean conditions and protected from contamination, rusting and shall not be in contact with soil throughout the length.

Ø  Covering shall be done with plastic sheet during monsoon season.

Ø  For stacking any hard platform or M.S. Stand shall be used which ensures no ground water contact & keep steel above the ground level.

Ø  The reinforcement shall be clean and free from oil, grease, and rust, loose scale, salt while receiving.

Ø  A single rack shall contain only same dia. of steel or proper partition shall be done for different dia of steel In-case of shortage of the space for keeping different dia of Steel.

Ø  Care shall be taken as the first in and fist out system is also followed for issue & steel shall be stacked accordingly.

Ø  All the stacked reinforcement steel shall be well identified with diameter of steel and tags shall be displayed  i.e. i) Tested and Approved, ii) Tested but Hold, iii) Rejected,

iv) Under testing

Ø  All the steel lot or Truck shall receive on site along with the MTC (Manufacturer Test Certificate).

Ø  The steel shall preferably bear the ISI stamp on it for the acceptance along with the grade of steel.

Ø  Testing of reinforcement steel shall be done as per frequency of testing & project requirement.

Ø  Reinforcement steel shall not be issued if it doesn’t meet the technical parameters.

Ø  Anti-rust coating shall be done as per procedure (if required).

 

Fig. Coated Steel

 

Step – 2 : Cutting & Bending of Reinforcement bars;

             

Fig. Steel Cutting Machine

 

Ø  BBS shall be prepared from approved detail drawing.

Ø  Cutting length shall be calculated as per IS : 2502.

Ø  Grade of rebars shall be as per specified in drawing or as per project specification.

Ø  Adequate care shall be taken to calculate length of a single piece rebar to avoid touching with form work at the ends.

Ø  Location of lap shall be provided as per drawing.

Ø  Location of lap also carefully chosen, if not specifically mentioned in the drawing, to avoid congestion at junction of beams and columns.

Ø  As a standard staggering of laps will be considered while making BBS.

Ø  Quantity of different diameter of rebar shall be calculated as per IS code for different structures.

Ø  Material shall be withdrawn from stores through requisition. Upon receipt from store, material shall be kept diameter wise close to the work place.

Ø  Only tested and approved bar shall be used for cutting and bending.

Ø  Cutting and bending of rebar is done either manually or through bar bending machine.

Ø  Shape, bend, hook, lap etc. are maintained during bar bending process as per drawing, BBS or as per relevant codes and specification.

Ø  Stirrups and small diameter finished bars shall be kept in groups for ease of handling.

Ø  Once bend, the bars should not be straighten up and re-bend for any reason whatsoever.

Ø  All cut & bars shall be stacked dia wise & size wise to avoid dislodgement of rebar during handling, transportation and placing.

Ø  Tagging can be done to avoid wasting of time for searching of required bars.

 

Fig. Steel Bending Machine

Step – 3 : Shifting & fixing of Reinforcement bars;

 

Ø  Cut & bend bars shall be shifted to work location by manually or mechanically and shall be kept tag wise or size wise.

Ø  Due care shall be taken in such situation to avoid dislodgement of rebar during handling, transportation and placing.

Ø  Cut & bend bar shall be kept over the ground or wet surface by using wooden batten or ply piece to avoid contact with soil & water.

Ø  Rebar shall be fixed in position either before or after completion of formwork. Say for columns and walls it is fixed in position prior to formwork however for slab and beam it is done after completion of formwork.

Ø  Sometimes, usually for footing or pile, rebar mesh or cage may be prepared in advance in a bar bending yard and placed or lowered on PCC mat or inside pipe casing.

Ø  Formwork should be completed in all respect in terms of leveling, closure of all gaps, removal of spacers, dirt, wooden pieces etc before placing of rebar.

Ø  Shuttering oil to be applied in advance and allowed to air dry. Any excess oil should be wiped off to avoid surface of rebar getting coated with oil.

Ø  Line, level, spacing of rebar should be maintained at site as stated in the intersection of rebar with binding wire adequately.

Ø  Bottom, side and end cover as stated in the drawing to be maintained. Special care shall be taken to avoid touching of rebar with formwork.

Ø  Maximum spacing of cover blocks shall not be more than 1 mt.

Ø  All reinforcement shall be free from loose rust, oil and any other substance likely to reduce the strength or durability of the bond between steel & concrete.

Ø  GI binding wire of 18 gauge thickness shall be used for fixing the reinforcement material or as per project specification.

Ø  The end of the binding wire shall be tucked inside to prevent corrosion spots in the concrete.

Ø  After completion of fixing of reinforcement, formwork shall be cleaned off all loose binding wires, cut piece rebar etc. before pouring concrete.

Ø  Due care shall be taken while placing bolts and inserts taking support of rebar. Position of such embedment shall be ensured by welding or any other appropriate method to avoid disturbance or shifting from designated position/alignment during concreting.

Ø  Upon completion of rebar work it should be offered for inspection and concreting should be taken up after pour clearance.

Ø  Scrap metal bin to be provided, so that scrap rebar can be disposed and proper housekeeping can be carried out at rebar yard / site area.

     

For Use of Coupler 

            

Ø  Coupler shall be used as per project requirements.

Ø  The couplers shall be tested as per project specification.

Ø  Every lot of coupler of each dia. & every lot of reducer shall be tested from the third party lab.

Ø  Every lot of coupler of each dia. & every lot of reducer shall be tested from the third party lab as per project testing frequency.

 

 For ready made cut & bend steel

              

Ø  Ready made cut & bend steel shall be stacked at site as per the shape, dia. location & source. No two shape, dia. Steel shall be mixed.

Ø  The grade of steel shall be conformed for its physical & chemical properties prior to use as per the sampling plan of the

Ø  The ready cut bend steel shall be checked with respect to the approved & shared BBS with the manufacturer.

Ø  The contractor shall prepare the Bar bending Schedule (BBS) as per the latest available  Structural drawing & Architectural layout along with the schedule of steel in accordance to IS 456, General drawing & in accordance of SP34 .

Ø  All bend allowance & other things shall be considered for the cutting & bending length for steel.

Ø  The BBS shall be prepared keeping in mind the required time line for cutting & bending at the factory.

Ø  The BBS shall be made as per the required format approved by the client or consultant.

Ø  If the steel is procured from the same vendor & cutting & bending is also done by same vendor; at the received of the consignment the steel shall be tested as per the dia.

Ø  The ready cut bend steel vendor shall share the production details to contractor for this regards for testing

Ø  All the ready cut bend steel shall be stacked well above ground on hard surface ensuring to deformation of bend steel, no mixing of different grade, shape & size steel with each other.

Ø  The stacked steel shall be properly identifiable by dia., shape lot, location & numbers along with received date & challan no. 

 

Reference Documents

 

Document Number	Document Title
IS 456	Plain Reinforcement concrete code practice
IS 2502	Code practice for bending and fixing of bar for concrete reinforcement.
IS 1786	Specification for High Strength Deformed Steel Bars & Wires for Concrete Reinforcement