To ensure that the installation of reinforcing bars are executed safely and in accordance with the contract requirements and that all quality assurance/ control activities are conducted in a systematic manner, works are inspected and conformance is verified and documented.
This method statement outlines the procedures to be followed in installation of reinforcing bars for:
- Ring beam Foundation for steel tanks
- Any auxiliary buildings
- Chambers (all types)
- At locations shown in the contract drawings and as directed by the Engineer.
3.0 DEFINITIONS, TERMS AND ABBREVIATIONS
CM Construction Manager.
SE Site Engineer
CS Chief Surveyor
ME Material Engineer
ESHO Environmental, Safety, and Heath Officer
ITP Inspection Testing Plan
The CM will coordinate with SE to ensure that the necessary resources to implement the approved Method Statement, have been allocated to the task.
The SE will ensure that the site preparation activities are conducted according to the approved method statement. The SE will also ensure that all in-situ tests, as required by the ITP are implemented.
The ME will ensure that the materials being used are in accordance with the Project Specifications and approved Material Submittals.
It is the site supervisor’s responsibility to organize the work in a safe manner to ensure that safety and protective equipment are being properly utilized. He must also ensure that the approved Method Statement procedure is followed and the ITP is applied.
Materials to be used shall be of Grade 60 according to ASTM A 615 Ductility Class B with its Yielding Strength more than or equal to 450MPa.
This materials shall be supplied by a recognized competent manufacturer and supplier accompanied by Testing Certificates, stating Purchaser Order No., Product or Material, Weight of Delivery, Diameter of materials, Cast Number, Yield Strength, Tensile Strength, Elongation and Chemical.
All Certificates shall show dates, Certificate Number and Authorized Signature of the manufacturer.
For Binding requirement (Tie Wires), the same procedure of documentation shall be made in the processing for the approval of these materials by the Engineer. All necessary Data shall be provided for his review to justify the conformity of the product.
- 25mm diam. Deformed Bars
- 20mm diam. Deformed Bars
- 16mm diam. Deformed Bars
- 14mm diam. Deformed Bars
- 12mm diam. Deformed Bars
- 5mm min. diam. Annealed Tie Wires
- 60mm PVC spacer
- Tarpaulin sheet for Temporary Covering
6.0 Tools, Plant & Equipment
- Mechanical Bender
- Electric Cut off wheel Steel Cutter
- Improvise Manual tools for bending
- Steel Hacksaw
- Steel Hooke and Mechanical Pliers for twisting Tie Wires
Latest revision of health and safety and environment plan will be implemented.
Following precaution shall be taken during work:
- Warning Sign and Warning Tapes for all the danger area.
- Lights at night and during dark time as a stand by unit.
- Safety personnel available anytime on site.
- Barricade and Warning Tapes including signboards will be installed in all areas not included in the installation of reinforcing bars to avoid entry of any person desist them from danger.
8.0 Prior Activities
Upon approval of this material by the Engineer, the material is purchased and delivered on site in a manner that it is carefully handled.
The material shall be properly marked with its Code, Separated from its sizes, Bundled so that it can be easily recognized before they shall delivered.
During delivery the materials shall be placed on a leveled position to avoid sagging and buckling that the materials are free from stresses.
It shall be covered by a tarpaulin or any equivalent material so that the reinforcement shall not be directly under the heat of the sun, exposed to dust and other foreign materials that affect the bonding and its composition.
This is also been observed on site where the materials are being separated and stocked in the storage.
After the delivery of the materials on site, the Engineer shall be informed of the delivery and request him for Inspection.
All the documents needed for the said inspection shall be prepared and visual inspection by the contractor should be a must before handing over to the Engineer. The following criterion shall be followed:
- The Steel Reinforcement shall free from Loose Milling Scale, and other foreign materials that destroy the bonds of the materials.
- Materials that are reduced in section and Transverse Cracks shall be removed from the stock.
Upon approval of the materials, fabrication of Stirrups and Bending of Main Reinforcement shall be started. Cutting list in coordination with the working drawings shall be considered and the following limitations shall be strictly observed:
- Cold Process for Cutting and Bending of the reinforcement shall only be allowed.
- Bended reinforcement shall not be re bended or straightened and re bended except specifically permitted by the Engineer.
- Partially embedded reinforcement shall not be bended on field if not permitted by the Engineer.
As soon as Lean Concrete is Casted and approved by the Engineer, including necessary materials needed for the installation of reinforcement such as:
- Specification or if there is stricter mentioned in the working plan.
- Spacers made up of Durable Concrete equivalent to 50 MaP Compressive Strength.
- Regarding Spacers shall be considered to uphold the durability of the structure.
9.0 Reinforcing Bars Installation Procedure
Installation of reinforcement to its final placement shall be made in consideration with the following materials and its specifications:
- Visual inspection shall be necessary to ensure that all bended main reinforcement is free from any Cracks and Bended in an angle prescribed on the plan.
- Splice of reinforcement shall be 60 times the bar diameter or if there is stricter specification mentioned in the approved plan for construction
- Lap joint shall be staggered it shall not be more than one third of the bars are lapped in the same area or in the same section. The specified length of the lap shall be increased by 50% of its length if the limitation is not fulfilled, unless it is specified on the working plan.
- Fixing of reinforcement using Tie Wire minimum of 1.50mm diameter annealed wire or similar, Shall be used.
- Binding wires for spacers shall be of Stainless steel or any equivalent material, all ties used shall be positioned in a manner as it is useful and twisted as far from the exposed surface as possible to ensure that the concrete covering shall not been deviated or distorted.
- Spacing of Tie Wires shall be tied in a spaces that the bars cannot move or slipped during fabrication and casting of concrete until it seated.
- Welding and Mechanical couplings for joints shall not be allowed as a means of binding the reinforcement.
All stirrups shall encircle the main reinforcement and hooked bent at its end and secured properly with tie wires at an appropriate distance to prevent slipping or movement during fabrication and casting of concrete, spacing of stirrups shall be according to the approved drawings.
Spacers shall be made of PVC material with 60 mm thickness for the ring beam and should be provided from well-known manufacturer.
Simplified Methods on Building Construction (Second Edition) by Max B. Fajardo Jr.
ASTM A615 Standard Specification for deformed bars and plain billet–steel bars for reinforce concrete.
Civil Engineering Handbook by W. F. Chen & JY Richard Liew (Section VI Chapter 48 to 52)
BS 4466 Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete.