Bar Bending Schedule (BBS) preparation and implementation are governed by various standards and codes that ensure accuracy, consistency, and safety in construction. These codes provide guidelines for the detailing, bending, and placement of reinforcement bars.
Key Standards and Codes for BBS
The following are the key standards and codes related to the preparation of BBS:
IS 2502: 1963 -
Code of practice for bending and fixing of bars for concrete reinforcement. This Indian Standard specifies the methods of bending, shapes of bars, and detailing rules for different structural elements.
SP 34: 1987 -
Handbook on concrete reinforcement and detailing. This handbook provides comprehensive guidelines on reinforcement detailing, including bar bending schedules, hooks, laps, and anchorage lengths.
IS 456: 2000 -
Code of practice for plain and reinforced concrete. This code lays out general requirements for reinforcement in concrete structures and serves as a reference for preparing BBS.
IS 13920: 2016 -
Ductile detailing of reinforced concrete structures subjected to seismic forces. This standard focuses on the reinforcement detailing required for earthquake-resistant construction.
BS 8666 -
Specification for the scheduling, dimensioning, bending, and cutting of reinforcement bars. Though a British Standard, it is often referred to for international projects.
Example of Standards Applied in BBS
Consider a column reinforcement design. The guidelines from IS 2502 and SP 34 are applied to determine the bending shape and anchorage lengths. The BBS for this column might look like the following:
Bar Mark
Diameter (mm)
Shape Code
Length of Each Bar (m)
Number of Bars
Total Length (m)
Weight per Meter (kg)
Total Weight (kg)
1
16
01 (Straight)
3.5
8
28.0
1.580
44.24
2
12
03 (L Shape)
1.5
12
18.0
0.888
15.984
The bending details and shapes are derived from IS 2502, ensuring compliance with standard practices.
Why Use Standards in BBS?
Standards and codes provide a framework that ensures:
Uniformity in reinforcement detailing across projects
Structural safety and durability
Efficient material usage and cost control
Adherence to legal and regulatory requirements
Conclusion
Adhering to standards like IS 2502, SP 34, and other relevant codes ensures the accuracy and reliability of Bar Bending Schedules. These standards not only enhance the quality of construction but also contribute to the safety and longevity of the structure.