RCC which is expanded to reinforced cement concrete is what the Civil Engineering field and Civil construction primarily depend on across the world. Technology had grown leaps and bounds, concrete has changed its form and properties for the good of construction in many ways, yet the integral part of RCC remains the same – the steel or the reinforcement it is embedded with. Refer to Reinforcement in Concrete for some more details on this.
This article details the method to provide reinforcement in RCC to comply with applicable standards and codes.
The purpose of this document is to detail the Procedure for installation of reinforcement works for Reinforced Concrete Frameworks in (Mention Project name). The documentation will apply to all Engineers, Workmen, QC personnel, and other concerned persons associated with the work.
2. Scope of work
This Procedure covers the applicable codes and standards, sequence of work to be followed for the rebar (reinforcement) work of different structural elements which includes but not limited to columns, slabs, walls, staircase construction, manpower requirements, tools and equipment required for the proper execution of works, quality and safety control measures required to complete the work in compliance to the required codes and standards.
The scope of work consists of
- Storage and control of materials
- Setting out
- Reinforcement installation for different structural elements
3. References & Standards
- Project Specific specifications
- IS 456 – PLAIN AND REINFORCED CONCRETE – CODE OF PRACTICE
- IS:2502 – CODE OF PRACTICE FOR BENDING & FIXING OF BARS FOR CONCRETE REINFORCEMENT.
- IS:1786 – REQUIREMENT FOR HIGH POWER DEFORMED STEEL BARS & WIRES FOR CONCRETE REINFORCEMENT.
- IS 16172 – REINFORCEMENT COUPLERS FOR MECHANICAL SPLICES OF BARS IN CONCRETE — SPECIFICATION
- IS:432 PART 2– MILD STEEL & MEDIUM TENSILE STEEL BARS & HARD STRAINED STEEL WIRES FOR CONCRETE REINFORCEMENT: PART-II -HARD DRAWN STEEL WIRE.
- IS:2751 – RECOMMENDED CARRY OUT FOR WELDING OF MILD STEEL PLAIN & DEFORMED BARS FOR REINFORCED CONSTRUCTION
- IS:5525 – SUGGESTION FOR DETAILING OF REINFORCEMENT IN REINFORCED CONCRETE WORKS.
- IS:9077 – CODE OF PRACTICE FOR DETERIORATION PROTECTION OF STEEL REINFORCEMENT IN RB AND REINFORCEMENT CONCRETE CONSTRUCTION.
- SP:34 – HANDBOOK ON CONCRETE REINFORCEMENT DETAILING.
- CPWD SPECIFICATIONS Volume 1 & 2 – GOVERNMENT OF INDIA CENTRAL PUBLIC WORKS DEPARTMENT
- IS 4082 – STACKING AND STORAGE OF CONSTRUCTION MATERIALS AND COMPONENTS AT SITE – RECOMMENDATIONS
- IS 9417 – WELDING – COLD-WORKED STEEL BARS FOR REINFORCED CONCRETE CONS‘TRUCTION – RECOMMENDATIONS FOR WELDING
4. Resources – a) Materials
The steel used for reinforcement shall be
(a) Mild steel and medium tensile bars conforming to IS 432 (Part I)
(b) High-strength deformed steel bars conforming to IS 1786.
(c) Hard-drawn steel wire fabric conforming to IS 1566.
(d) Structural steel conforming to Grade A of IS 2062.
(e) Thermo-mechanically treated (TMT) Bars.
Thermo Mechanically treated reinforcement bars:
The TMT bars shall conform to IS 1786 pertaining to Fe 415 D or Fe 500 D or Fe grade of steel as specified.
Selection and preparation of Test sample.
Test pieces shall be collected from the bar or coil in the presence of the authorized person. The test pieces obtained shall be further modifications. No deduction in size by machining or otherwise shall be permissible. No test piece shall be enacted or otherwise subject to heat treatment. Any straightening which a test piece may require shall be done cold. Required tests are
Tensile Test: 0.2% proof stress and percentage elongation – Shall be done as per IS 1608, read in conjunction with IS 226.
Retest: This shall be done as per IS 1786.
Re-bend test: This shall be done as per IS 1786
(Down load the document for tolerance details in its properties)
Project Engineer, Site Engineers, Supervisors, Foremen, and helpers.
5. Safety Precautions
- Safety of the personnel and properties is to be given prime importance and all works to be carried out without causing any accidents or property damages.
- Plywood and other related materials shall be stacked properly near the place of work (Do not stack too large quantity near the work area thereby causing safety hazard).
- Height of the stack should not be more than one and half meter.
- Scaffolding to be braced adequately.
- Working space to be clear of rubbish, waste mortar etc so that easy access and cleanliness is ensured.
- Scaffolding to be checked for the load carrying capacity and ensure no overloading.
- Lifting, manual transporting of conventional formwork materials etc must be carried out by workers who are properly trained. Otherwise, this may cause serious injuries to workers.
- Throwing of debris from height strictly prohibited.
- Before commencement of block work in front of lift shaft safety permit should be taken.
- CT props to be fixed in front of lift shaft to tie the safety belt.
- Hard barricading to be cut only by gas cutting (If any anchored in concrete along the openings and edges of the building).
The Project Manager/Construction Manager shall be responsible for the overall implementation of this procedure.
- Approved Good for construction drawing with latest revision issued shall be available with the construction team
- Shop drawings: Shop drawings for reinforcement shall be approved, stamped for GFC as per the contractual requirement if any.
8. Equipment and Tools
- Bar cutting equipment
- Bar bending machine.
- Bar tying and cutting player.
- Equipment to enable safe working at height.
9. Work procedure;
Construction procedures should be planned in advance to ensure the safety of personnel and equipment and the integrity of the finished structure.
Reinforcement shall be clear and free from loose mill scales, dust, loose rust, coats of paints, oil, or other coatings which may destroy or reduce bond. The oily substance shall not be used for removing the rust prior to assembly of reinforcement.
Cutting and Bending of Reinforcements
- As per the construction program and the priority, the cutting and bending of steel reinforcement for that particular structural element will commence as per the approved shop drawings and bar bending schedule or BBS.
- The cut length will be marked with a steel measuring tape, as shown in the BBS.
- The bar will be cut with a shear line cutting machine.
- For straight bars, after cutting the required numbers, it will be bundled and tagged with bar mark number and stack for delivery to site/required location.
- For stirrups and cranked bars, the cut bars will be taken to the bending machine and bend as per dimensions in the BBS. During the bending process re-check randomly with a template for dimensions.
- Bars shall be bend cold with any suitable equipment such as hand operated machines or power operated machines which mainly depends on the size of rebar. Normally the methods are by using
- Mandrel and claw which can be used for bending bars up to 12mm as per the standards.
- Simple bar bending machine which consist of mandrel, socket and a hole
- Geared bar bending machine that have different parts such as mandrel, hole, ratchet lever, plain roller, grooved roller and spindle.
- Wherever facility for electric arc welding or gas pressure welding is available, welding of bars shall be done in lieu of overlap. The location and type of welding shall be got approved by the Engineer-in-Charge. Welding shall be as per IS 2751 and 9417.
- Upon completing the required numbers, bundle and tag the bars with bar mark number and stack for delivery to the site.
- Binders, stirrups, links etc. the straight portion beyond the curve at the end shall be not less than eight times the nominal size of bar.
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