As we know Bar bending schedule for footing provides us information on the total quantity of steel rods, length of steel rods required and Cutting length of a steel rod at the site. So in this article we will see how we can do it.Here we can see below the reinforcement detail of an isolated footing. The total length and width of a column are 2500 mm and 1500 mm respectively. The height of footing is 300 mm.Now let us calculate bar bending schedule for footing step by step.
Given,
Diameter of Both bars in X direction and Y direction are 12mm.
Clear cover of the footing is 50 mm.
C/C centre to centre spacing of steel rods is 150 mm.
Reinforcement detail for bar bending schedule for footing
step-1 in this step we will calculate the effective length of steel rod in x-direction and y-direction using the given formula
Effective length = Total length – both sides cover
Calculation
Effective length along X direction = 2500 – (2 x 50) = 2400 Mm
Effective length along Y direction = 1500 – (2 x 50) = 1400 Mm
Step-2 Calculate numbers of bars by using formula given below.
No of bars = (Effective length / spacing) + 1
Use Spanning of steel rod as mentioned above.
No. of bars along (X) direction = (1400/150) + 1 = 10 nos.
No. of bars along (Y) direction = (2400/150) + 1 = 17 nos.
Step-3 Calculate Cutting length of Steel Bars using formula below
Cutting length of bar along (X) direction:
(Effective length + bends) – bend deductions
[2400 + 2(300 – 50 – 50)] – (2 x 2 x 2) = 2792 mm or 2.792m
Cutting length of bar along (Y) direction:
(Effective length + bends) – bend deductions
[1400 + 2(300 – 50 – 50)] – (2 x 2 x 2) = 1752 mm or 1.75 meter.
Bend deduction is calculated as given Below
Deduction of the length of bars due to bending at a different angle:
45 Degree = 1d
Deduction of the length of bars due to bending at a different angle:
45 Degree = 1d
Step-4 Calculate total length of steel Rods
Along (X) direction = No. of bars x Length of one bar = 2.792x 10 = 27.92 meter
Along (Y) direction = No. of bars x Length of one bar = 1.75x 17 = 29.75 meter
Step- 5 Calculate the unit weight of steel rod using formula
Total Weight of steel = Unit weight x Total Length of steel rod.
Add 5% of wastage of steel to get actual total weight of steel bars
