A Bar Bending Schedule (BBS) is an essential tool for managing reinforcement bars in construction. Among the key parameters in a BBS table are the **Shape** and **Type** of bars, which provide details about the geometry and functional role of the reinforcement. This article explains these parameters and includes examples.
The shape of a bar in BBS indicates its geometry as per the design requirements. Standardized codes or descriptions are used to represent the shape of the bars, ensuring clarity and accuracy in construction.
Common shapes include:
The type of bar in BBS refers to its functional role in the structure. Different bars are used for various purposes like resisting tension, compression, or shear. Examples of bar types include:
Shape: Straight Bar
Type: Main Bar
Description: A straight reinforcement bar typically used as the main reinforcement in slabs and beams.
Example Entry in BBS Table:
| Bar Mark | Shape | Type | Diameter (mm) | Length (mm) | Quantity |
|---|---|---|---|---|---|
| S-16-01 | Straight | Main Bar | 16 | 5000 | 20 |
Shape: Rectangular Stirrups
Type: Shear Reinforcement
Description: Closed-loop bars used to resist shear forces in beams and columns.
Example Entry in BBS Table:
| Bar Mark | Shape | Type | Diameter (mm) | Dimensions (mm) | Quantity |
|---|---|---|---|---|---|
| ST-8-01 | Rectangular | Stirrup | 8 | 300 x 500 | 25 |
Shape: Cranked Bar
Type: Main Bar
Description: A bar with cranks used in slabs and beams to provide support in both tension and compression zones.
Example Entry in BBS Table:
| Bar Mark | Shape | Type | Diameter (mm) | Length (mm) | Bend Details | Quantity |
|---|---|---|---|---|---|---|
| B-12-02 | Cranked | Main Bar | 12 | 3000 | 45° at 1000mm | 10 |
Shape: L-Shape Bar
Type: Anchorage Bar
Description: Bars bent at right angles to provide anchorage in footings and columns.
Example Entry in BBS Table:
| Bar Mark | Shape | Type | Diameter (mm) | Leg Dimensions (mm) | Quantity |
|---|---|---|---|---|---|
| L-10-01 | L-Shape | Anchorage Bar | 10 | 500 x 300 | 15 |
Understanding the shape and type of bars in a BBS table is crucial for effective reinforcement planning and placement. Each shape and type serves a specific purpose, ensuring the structural integrity and efficiency of construction projects.