Points to be verified prior to concrete footings
After preparing the footings for concreting i.e. reinforcement is totally joined, It is necessary to check the work cautiously. It is recommended to start the examination process in two stages.
01. Examine Formwork and soil strata
Prior to arrange reinforcement, carefully examine the formwork and soil strata. It is very crucial because it becomes difficult to rectify some types of formwork faults once reinforcement is set in desired location.
02. Examine Reinforcement
Carefully examine to ensure that the reinforcement is arranged with adherence to exact size and spacing provided in the structural drawings. Therefore, it is a standard engineering exercise to verify the formwork prior to set or bind reinforcement.
01. Centering and shuttering/Formwork:
Prior to start the shuttering & centering/formwork for footing, the points, given below, should be taken into consideration.
- Verify the centre lines/margin from boundary etc. out of reference column/bench mark pillar. Examine all statutory margins from the road and all remaining boundary according to law and drawing are maintained properly. Also, examine orientation relating to North.
- Make sure that the foundation is laid at a planned depth according to drawing.
- Size of formwork box should have the similarity with the drawing and it should be formed with permitted materials.
- The formwork should have been dry and washed cautiously prior to employ mould release agent. The similar type of release agent should be utilized all through the equivalent formwork materials.
- The formwork surface should have been uniform and finely coated with mould release agent.
- The mould release agent should not be touched with reinforcement or the hardened concrete because it can impact the bond among steel and concrete.
- The height of shuttering should have the similarity with the height of pedestal and joint should have been closed to resist the possibility of any leakage of the cement slurry.
- Footing box should be perfectly supported to facilitate location of footing box to be unchanged throught concreting.
- Nail on planks or footing box should be used to mark the center of the footing.
- Shuttering for foundations should be stronger in all seasoned condition i.e. dry, rainy or existence of ground water
- Prior to tie reinforcement, the shuttering should be approved by the engineer-in-charge or supervisor.
- Check that no earth collection on C.C. exists prior to tie reinforcement.
- For adequate foundation depth, make sure that the excavated earth does not slide or fall unless it is refilled. Carry out exact shoring and shuttering. Make sure that the ladder etc is perfect to enter the pit and come out. Besides, check the safety of the working labour.
- There should not be any type of loose scale, rust, mud, or oil in the reinforcement steel.
- Reinforcement of footing mesh (jali) should be cut on the basis of bar bending schedule.
- After binding the bars, footing mesh should be arranged. Each and every, bar junction should be fastened with binding wire of permitted gauge.
- The bend (‘ L ‘) in mesh should be set with 90° and bar should be in ascending direction.
- The center of the footing mesh should be similar with the center of the footing.
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