Bar Bending Schedule, abbreviated as BBS, is a structured list that provides detailed information about reinforcement bars used in construction projects. It includes specifics such as the type and size of bars, bending details with accompanying sketches, individual and total lengths, as well as overall weight.
Breaking Down BBS
In the realm of Reinforced Cement Concrete (RCC) work, a distinct schedule is formulated for each type of job. BBS plays a crucial role in this process, as it facilitates the identification and arrangement of bars of varying sizes and lengths during construction. It furnishes essential information like:
- Specific size and type of bars
- Bending details (if applicable) with a visual representation
- Quantity of sets or individual bar counts per set
- Length in meters, both individual and total
- Weight per unit length and the cumulative weight.
Significance of Bar Bending Schedule
Given that on-site laborers might not possess advanced technical knowledge, elucidating through drawings alone can prove challenging. This situation can lead to incorrect cutting and bending of steel. The BBS, with its inclusion of bar shapes and cutting lengths, serves as a vital tool for effective communication.
A supervisor can easily instruct the labor force, ensuring adherence to structural design specifications and requirements.
Advantages Offered by Bar Bending Schedule
The implementation of BBS brings about several advantages, promoting efficiency and quality in construction projects:
- Accelerated work progress, leading to reduced costs and construction time.
- Minimization of wastage during reinforcement cutting.
- Enhanced quality control on-site.
- Improved inventory management at the construction site.
- Acts as a deterrent against theft by providing a tracking system.
- Facilitates swift billing for construction services.
- Assists in estimating the quantity of steel required.
Applications of BBS
The Bar Bending Schedule finds application in various crucial aspects of construction:
- Determining the overall steel requirement for a given structure, aiding in cost estimation for tenders.
- Establishing cutting and bending dimensions for reinforcement, thereby enhancing construction quality and economizing steel usage.
- Allowing for pre-fabrication of reinforcement at the factory, enabling faster construction and cost savings.
- Offering clarity to site engineers for verification of reinforcement cutting and bending prior to concrete placement.
Essential Guidelines for Preparing Bar Bending Schedule
In order to create an effective BBS, the following rules should be adhered to:
- Group bars by structural unit and list them separately for each floor.
- Arrange bars in ascending numerical order for clarity.
- Employ unique labels for each bar bundle, incorporating key specifications (bar length, size, and shape).
- Ensure that bar type and shape conform to BS 8666 standards.
- Attach bar mark references to bundles, uniquely associating them with a specific set or group.
- Perform cutting and bending length calculations separately, excluding them from the detailed list.
Step-by-Step Guide for Preparing a Bar Bending Schedule
A comprehensive BBS should encompass the following details:
- Bar description
- Shape and bending dimensions
- Number of bars of the same type
- Individual bar length
- Total bar length
- Bar diameter
- Weight per unit length
- Total weight.
While most of these details can be found in the drawings, the cutting and bending lengths, as well as total weight, require separate calculation. For instance, the length of one hook can be determined as 9 times the diameter (9D), and the total length of a straight bar with hooks at both ends can be calculated as the sum of the original length (L) and 18 times the diameter (18D).
