CHECKLIST FOR COLUMN REINFORCEMENT

Checking of column reinforcement steel



  • Following points should be checked before column casting.

  1. The reinforcement steel should be free of any loose scale, rust, mud, or oil.
  2. Main reinforcement and ring of column should be cut as per required length.
  3. The stirrups should be carefully cut in length as extra length will result in large size of stirrups/ rings resulting in less cover to concrete, which is never advisable.
  4. When a column reinforcement is rested on the reinforcement of footing or mat, special confining reinforcement (main vertical bars) should be extended at least 300 mm or as per drawing.

Typical Column Formwork
  • Column Reinforcement Extended Upto 300 mm in Footing
  1. In a reinforced column, the area of longitudinal reinforcement shall not less than 0.8 percent or more than 6 percent of the gross cross-sectional area of the column as per IS code.
  2. A minimum number of 4 bars shall be provided in a square or rectangular column and six bars in circular column with helical reinforcement.
  3. The bars shall not be less than 12 mm in diameter and spacing of the bars along the periphery of the column shall not exceed 300 mm.
  4. Longitudinal bars shall not be spaced more than 75 mm on either side, transverse reinforcement need only to go round corner and alternate bars for the purpose of providing effective support.
  5. The diameter of the rings or ties shall be not less than one- fourth of the diameter of the largest longitudinal bar and in no case less than 6 mm. However, we recommended 8 mm diameter bars,
  6. Main reinforcing bars and stirrups should be tied tightly to each other by using binding wire of proper gauge, preferably 16 gauge.
  7. Check the size of stirrups before tying. Hook angle in link or stirrups should be 135°.This is very important from seismic considerations. This alone will increase your buildings capacity to withstand earthquake force. Hence very important.


Proping angle
  • Column Stirrup Hook
  1. Lapping should be provided in the central half of the member length and lap length should be 45D (D is the diameter of the bar) or as per concrete grade. In central half of member, the lapping of bar should be alternate if possible.
  2. Lapping should be in joggle if diameter of bar is more than 12 mm.
  3. Spacing near support should be less than middle portion of column.
  4. Before placing the concrete, Check the reinforcement details with bar bending schedule and get an approval from structural consultant.

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