Bar Bending Schedule of Column Footing

Bar Bending Schedule is very important to determine quantities of Steel reinforcement toward each element of the building.

The following steps are involved to work out the Bar Bending Schedule of Column Footing :-

Prior to start the calculation, go through the footing drawing and record the following crucial points :-

1. Footing (Length,Width,Thinkness)
2. Diameter of footing reinforcement
3. Grate of reinforcement
4. Distance of the reinforcement(c/c)
5. Hook’s length(If necessary)
6. Concrete covers of the footing (Top and Bottom)

Illustration: Assume, there is a column footing with a length 2m,width 2m and thickness 0.250m.The main bars is 12mm @ 150c/c and distribution bar is also 12 mm @150 c/c. The footing clear cover is 50 mm from top and 75mm from the bottom. Work out the number of the steel that should be utilized in this column footing on the basis of the following data :-

Length of the Footing = 2m
Width of the footing = 2m
Thickness = 0.250m
Main bar = 12mm @ 150c/c
Distribution bar = 12 mm@150 c/c
Clear cover =50 mm form top and sides and 75 mm from bottom

SOLUTION: Initially, it is necessary to work out the number of the bars employed in footing.

After that, it is required to work out the cutting length of the bars and finally, work out the weight of the reinforcement bars.

Footing Main Bar’s
= (Total didtance – clear cover) / c/c +1
= (2 m – (0.05+0.05) / 0.15 + 1
= 14 Bars

Cutting length of one main bar in footing:

Formula:
= {Total length – 2(Half diameter of the bar + clear cover) + 2(Thickness of the slab – Bottom and top clear cover – Half diameter of the bar)}

Length of 1 Main Bar:
= 2 m – 2 (0.006 + 0.05) + 2 (0.250 – 0.075 – 0.05 – 0.006)
= 2 m -2 (0.112) + 2 (0.119)
= 2 – 0.224 + 0.283
= 2.059 m

Weight of the bar:
= D ²/ 162.2 x Length
= D ²/ 162.2 x 28.826 m
= 25.32 kg

To learn the calculation process of footing distribution bar, go through the following link www.onlinecivilforum.com