Difference between Main Bars and Distribution Bars
Main reinforcement bars placed in bottom of distribution reinforcement bars. Distribution bar placed on top of main bars. Main bars are placed at the shorter span direction, to transfer the bending moment at the bottom of the slab to the beam.
Distribution bars are used in the slab to resist the shear stress. Because the cracks are developed due to shear stress on the top of the slab.
Main Bars:
- It resist bending moment.
- It resist tensile stress produced in the slab.
- It resist superimposed and dead load of the slab.
- Diameter of main bar should not less than 8mm(HYSD bars) and 10mm for plain bars.
- Diameter of main bar is always grater than distribution bar.
Distribution Bars:
- It distribute the superimposed load equally to the main bars.
- It resist temperature stress produced in the slab due to temperature variations.
- It maintain the main bars in their proper position (spacing).
- Diameter of distribution bar should not less than 8 mm.
- Diameter of distribution bars always less than main bars.
Main reinforcement bars and distribution reinforcement bars are two types of steel bars used in slabs.
Main reinforcement bars are thick and strong. They provide primary support to the slab, helping it to withstand heavy loads like furniture and people. Main bars are placed parallel to each other and are spaced closer together to ensure the slab's strength and durability.
On the other hand, distribution reinforcement bars are thinner and are placed perpendicular to the main bars. They help to spread out the load evenly across the slab. These bars are not as strong as the main bars but play a crucial role in reinforcing the slab, especially in areas where there might be concentrated loads.
In simple terms, main bars bear the main weight, while distribution bars help to distribute the weight evenly across the slab. Both types of bars work together to make the slab strong and sturdy.
