Checklist for column reinforcement./ Points to be checked in column reinforcement.

  Following are the 11 points that should be checked in the column reinforcement work before concreting.

1. Quality of bar:

The steel bar should be straight & fresh, having a blackish-grey color in appearance. The rusted rebar should be avoided as they have low bonding strength with the concrete. The ribs over the bars should be uniform in their thickness without any breaks in them.

2. Grade of steel:

The grade of the steel bar should be chosen, as mentioned in the reinforcement detail drawings. You can find the grade of steel embossed over the bar, as shown in the above image. 

Checking the steel grade is a must, as it indicates the yield strength & decides the load-carrying capacity of the rebar. 

3. Plumb check:

The column reinforcement should be checked for its verticality so that the clear cover should be uniform from the shuttering formwork.

 There should not be any twist in the tied reinforcement bars when compared at the top & bottom end of the rebar.

4. Clear cover:

The column cover blocks should be used to maintain the equal clear cover as mentioned in the drawing.

If you are using circular cover blocks, care should be taken to insert them in the lateral ties at the required intervals to maintain a clear cover from the concrete.

5. Diameter & spacing of bar:

 

The column bar diameter should be checked before anchoring the lateral ties to them. The column reinforcement may contain bars of different diameters according to the structural design.

The c/c spacing between the two bars should be measured as per the drawings. 

If not mentioned in the drawing, the bars are placed at an equal c/c distance in the given axis, as shown above.

6. Dia. & spacing of lateral ties:

The diameter &  c/c distance between the lateral ties should be checked before erecting the formwork. The lateral ties should be perpendicular to the main bar & there should not be any ups & downs in their periphery.

7. Hook length: 

The hook's length of the lateral ties should be measured before we tie them to the main bar. If not mentioned, we can calculate them as 10d, where d is the diameter of the bar.

The corner bend should be at 90°, & the angle at the hook bend should be 135°, as shown above.

8. Lateral tie position:

The c/c distance of the lateral ties varies according to the column zone & lapping zone of the reinforcement. In the lapping zone, the lateral ties are closely spaced as shown above.

Care should be taken that, there should be at least one lateral tie above the concreting level of the column.

9. Development length:

The development length of the column reinforcement should be checked for its proper length as per the drawing, to achieve the designed bond strength.

Go through: What is development length in construction? / Reasons for providing development length & factors affecting it.

10. Bar lapping:

The lapping of the bar should be staggered as shown above. The top end of the column bar should not be at the same level if further lapping is needed for the column extension.

Go through: What is lap length in reinforcement bars?/ General rules while providing lap length.

11. Binding wire:

Once the binding wire is tied at the corner of the lateral ties, the wire knot should not be protruded into the concrete cover area. Give instructions to the workers to push them within the reinforcement area, so that the construction quality is maintained.

For you 👇

❤ Different types of rebar ties/Different ways of tying rebar with binding wire.

Thank you for going through this article❤. Have a good day😄.

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