Important Purposes of Chair bars
Important Purposes of Chair bars
Chair bars, also known as spacer bars or distance bars, are crucial components in reinforced concrete construction. They serve several important purposes:
- Maintain spacing between reinforcement layers: Chair bars are placed between two layers of steel reinforcement, typically in slabs, beams, and foundations. They ensure that the concrete cover over the bottom layer of reinforcement is maintained at the specified thickness. This is crucial for the structural integrity of the concrete element, as the concrete cover protects the steel from corrosion and fire.
- Enhance stability of reinforcement: Chair bars help to hold the reinforcement cage in place during concrete placement and prevent it from shifting or moving. This is especially important in areas where the concrete is subjected to heavy loads or vibrations.
- Improve concrete flow and consolidation: Chair bars create space between the reinforcement layers, which allows the concrete to flow more easily and be properly consolidated. This helps to prevent voids and honeycombs in the concrete, which can weaken its strength and durability.
- Reduce the risk of cracking: By ensuring proper spacing and stability of the reinforcement, chair bars help to reduce the risk of cracking in the concrete. This is because they allow the concrete to shrink and expand uniformly, without putting undue stress on the reinforcement.
Overall, chair bars play a vital role in ensuring the quality and durability of concrete structures. They are a relatively small and inexpensive component, but they have a significant impact on the overall performance of the concrete.
Here are some additional points to note about chair bars:
- The size and spacing of chair bars will vary depending on the specific application.
- Chair bars can be made from different types of steel, but they are typically made from the same type of steel as the main reinforcement.
- Chair bars are typically installed by tying them to the main reinforcement using wire or by welding them together.