Distribution bars placed on the top of the main bar. Main reinforcement bars are used to transfer the bending moment developed at the bottom of the slab. Distribution bars are used to hold the slabs on either way and to resist the cracks and shear stress developed at the top.
Why we provide distribution Steel in slab? Why we provide distribution Steel in slab?
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Distribution steel is mainly provided on the top of the main bar, hence placed in longer span direction. The main purpose of providing distribution steel are used to hold the slabs on either way and to resist the cracks and shear stress developed at the top. It also helps to take care of temperature stresses and shrinkage.
Distribution steel in slab: The most important purpose of distribution steel in transverse direction is to provide a proper hold to the main steel in position & to take care of shrinkage as well as stresses.
The name itself defines the meaning of the word.
Distribution bar n a reinforced concrete slab is placed usually at right angles to the main reinforcement bar, intended to spread a concentrated load on the slab and to prevent cracking and other types of failure. It is also known as a Secondary bar.
The following point should keep in mind while understanding the distribution bar.
● The distribution bar is having a small diameter than the main bar.
● The distribution bar always place on the top of the main bar.
● Distribution bar placed in a longer span
Porpoises why we providing distribution steel in slab
● Distribution steel is provided to prevent the shrinkage stresses and temperature effects. Due to this, cracks are formed on the top of the slab; hence crack are neglected.
● To distribute the load equally to the main bars, hence decreasing the effect of point load on the slab.
● Distribution bars are also provided to Stability for the main bars, and they also help to keep the main bars in position.
●This steel distributes the localized loads, so the concentrated stresses are reduced & more even throughout the slab. The distribution reinforcement, in most cases, is designed for strength. But sometimes main porpoises to provided for other reasons like cracking, load distribution, etc.
Distribution reinforcement is given to deal with shrinkage stress and temperature effects. After pouring of cement, at the time of curing, concrete will contract since the water in the concrete gets used for hydration. As the slab is inflexibly fixed at the ends, this shrinkage will be limited by the support, which will prompt liable tensile stress in the slab. As the concrete is weak in tension, to take care of these tensile force distribution, reinforcement is given. The same thing will occur in temperature variation too. As the temperature falls, the slab will attempt to contract.