Bar Bending is the process of cutting, bending, and fixing the reinforcement bars as per drawing. But what about the bar bending schedule? Why do we need it?Â
Take the below diagram of reinforcement details of a beam that lists all the details in comprehensive mode. It is the end result of the structural design.
The responsibility of the structural engineer has been completed by suggesting the right reinforcement bars to the structure. But at the site, many people need to understand the reinforcement details in a simple manner for their responsibilities.
What is a Bar Bending Schedule?
Bar Bending Schedule is a definitive list of reinforcement bars for any structural element that includes a mark, shape, size, location, length, and bending details of the reinforcement. It is often referred to as BBS.
Tabular view representation of each reinforcement bar used in any structural element is known as BBS.
Guidelines to Follow
Before preparing, make sure to follow the below guidelines
 Every RCC structural element should have a separate BBS. Do not group them as one.
 Ensure to follow the IS guidelines for bending, hook length, lap length & development length calculations.
 It would be handy if you memorize the unit weight of steel bars.
 Ensure the estimation by thumb rule calculations of steel reinforcement for different structural members.
 Keep Bar Bending Shape Codes handy for easy reference.Â
BBS Basics & Formulas to be remembered
 Diameter of bars (in mm) â€“ 6, 8, 10, 12, 16, 20, 25, 28, 32, 36, 40 mm
 The standard length of reinforcement bar â€“ 12 metre or 40 feet
 Weight of bar (Kg) per metre formula â€“ D2/162Â
 Extension Length Formulas




 Footing lap length formula â€“ 40d
 Column Lap length formula â€“ 50d
 Development length for dowel bars â€“ 16d
 Hook Length â€“ 9d




 Concrete Cover




 Footing â€“ 75 mm
 Column & Beam â€“ 2550 mm




 Bend Deduction




 45Â° â€“ 1d
 90Â° â€“ 2d
 135Â° â€“ 3d




 Crank Length Formula




 45Â° â€“ 0.42d
 30Â° â€“ 0.27d
 60Â° â€“ 0.58d




 Extra Bars Length â€“ L/4 or L/5
Preparation of Bar Bending Schedule
As said earlier, bbs is a definitive list of reinforcement requirements.Â
 It suggests how much steel to be procured?
 It instructs the contractor to plan the weekâ€™s steel purchase.
 It instructs the bar bender to fabricate the reinforcement into the desired shape as per the structural drawing.
 It instructs the quantity surveyor for the proper estimation of the material.
How do you make a bar bending schedule?
Each structural element will be prepared separately either for each floor or for the entire building. We have discussed the bar bending schedule for different structural elements such asÂ
Any BBS has only five steps of calculation such asÂ
 Find the number of reinforcement bars to be used
 Find the cutting length of each bar
 Find the number of stirrups calculation or number of distribution bars calculation if it is a slab
 Find the cutting length of stirrups or extra bars (top rods)
 List down all the bars into the table and find out the quantity of steel.
As simple as that.
Example Bar Bending Schedule
Cutting Length of Bottom Bar = Lclear â€“ (2x concrete cover) + (2Ã—500)
= 3000 â€“ (2Ã—40) + (2Ã—500) = 3920 mm
Cutting Length of top bar =Â Lclear â€“ (2x concrete cover) = 3000 â€“ (2Ã—40) = 2920 mm
Step 2 â€“ Number of Stirrups
Number of Stirrups = (Length of Beam / Spacing) + 1 = (3000/200) + 1 = 16 numbers
Step 3 â€“ Cutting Length of Stirrups
Cutting Length of stirrup = Perimeter of stirrup + (3 x 90Â° bend) + (2 x hook length)
= 2 ( 520+220 ) + (3 x 2d) + (2x1d) = 1480+(3x2x10)+(2Ã—10) = 1560 mm
Bar Bending Schedule Format
Bar Shape  Dia of Bar  Cutting Length  Number of Bar  Length of Bar (mm)  
8  10  12  16  20  
10  3920  2  â€“  7840  â€“  â€“  â€“  
10  2920  2  â€“  5840  â€“  â€“  â€“  
8  1560  16  24960  â€“  â€“  â€“  â€“  
Total Length (m)  24.96  13.68  â€“  â€“  â€“  
Weight Per Metre (Kg/m)  0.4  0.62  0.89  1.58  2.47  
Total Weight in Kg  9.984  8.482  â€“  â€“  â€“ 
Happy Learning ðŸ™‚
3 Comments
Useful for the site engineers who work on reinforcement job.
Thanks, all in one place reinforcement schedule
I want to know cutting length of box culverts