Parameters of a BBS Table: Total Length and Weight in BBS
In a Bar Bending Schedule (BBS), **Total Length** and **Weight** are crucial parameters for estimating the quantity of reinforcement steel required for a project. These parameters provide a clear understanding of the total steel needed, aiding in procurement and ensuring cost-effective material usage. This article explains how to calculate the total length and weight of bars, with examples.
1. Importance of Total Length and Weight in BBS
The total length and weight are important because they:
- Provide an accurate estimate of the required reinforcement steel.
- Help in planning and procuring materials efficiently.
- Minimize wastage by ensuring precise cutting and bending.
- Assist in tracking and managing steel inventory on-site.
2. Calculation of Total Length
The total length is calculated as:
Total Length = Length of Each Bar × Number of Bars
3. Calculation of Total Weight
The weight of steel bars is calculated using the formula:
Weight (kg) = Total Length (m) × Unit Weight (kg/m)
The unit weight of steel bars is derived from their diameter using the formula:
Unit Weight (kg/m) = (d² / 162), where **d** is the bar diameter in millimeters.
4. Examples of Total Length and Weight in BBS
1. Straight Bars in a Slab
Details:
Length of Each Bar = 6m
Number of Bars = 20
Diameter of Bar = 12mm
Total Length: 6 × 20 = 120m
Unit Weight: (12² / 162) = 0.888kg/m
Total Weight: 120 × 0.888 = 106.56kg
Example Entry in BBS Table:
Bar Mark | Shape | Diameter (mm) | Length of Each Bar (m) | Number of Bars | Total Length (m) | Total Weight (kg) |
---|---|---|---|---|---|---|
S-12-01 | Straight | 12 | 6 | 20 | 120 | 106.56 |
2. Stirrups in a Beam
Details:
Length of Each Stirrup = 1.744m
Number of Stirrups = 30
Diameter of Bar = 8mm
Total Length: 1.744 × 30 = 52.32m
Unit Weight: (8² / 162) = 0.395kg/m
Total Weight: 52.32 × 0.395 = 20.66kg
Example Entry in BBS Table:
Bar Mark | Shape | Diameter (mm) | Length of Each Bar (m) | Number of Bars | Total Length (m) | Total Weight (kg) |
---|---|---|---|---|---|---|
ST-8-01 | Rectangular | 8 | 1.744 | 30 | 52.32 | 20.66 |
3. Cranked Bars in a Beam
Details:
Length of Each Bar = 5.721m
Number of Bars = 15
Diameter of Bar = 16mm
Total Length: 5.721 × 15 = 85.815m
Unit Weight: (16² / 162) = 1.580kg/m
Total Weight: 85.815 × 1.580 = 135.59kg
Example Entry in BBS Table:
Bar Mark | Shape | Diameter (mm) | Length of Each Bar (m) | Number of Bars | Total Length (m) | Total Weight (kg) |
---|---|---|---|---|---|---|
CB-16-02 | Cranked | 16 | 5.721 | 15 | 85.815 | 135.59 |
5. Conclusion
The total length and weight of reinforcement bars are essential parameters in a BBS, ensuring precise material estimation and efficient resource management. By following standard formulas, construction teams can reduce wastage, control costs, and maintain structural integrity.