R.C.C. stands for Reinforced Cement Concrete, and now a days is the main Constructional Material which is used to construct different structural parts, by using R.C.C. it has been made possible to construct High Rise Buildings which were formerly only constructed with Pure Steel Structure but by using R.C.C. in the modern age it has now become an easy and economical approach to attain such high strength to withstand such tremendous imposing loads on structure.

R.C.C. is actually consisting of two main different parts firstly Concrete and secondly Reinforcement in the form of Steel. As we all know that when ever loads come on a structure it tries to take the shape of bending, and the nature of bending depends upon it’s supports and their respective positions. When the shape of bending takes a shape convexity downward then it’s called as Sagging and the Bending the an corresponding Bending Moment is Treated as +ve , and when the shape of the bending takes a shape of convexity upwards then it’s called as Hogging and the Bending and corresponding Bending Moment is treated as –ve.

### Why Reinforcement is Needed?

Due to the bending of a structure one side of the structure about Neutral Axis Compresses and the other side is tensed, due to the above fact Compressive Stress and Tensile Stress develops in the structure from the Neutral Axis towards the Extreme Fiber that is the exterior face of the structure in a increasing manner in terms of magnitude of the stresses. So the Structure is having both Compressive and Tensile Stresses in it.

In the case of a Concrete, it has enough resistance against Compressive Stresses but it is very very Weak in Tensile Stresses and it can only resist a very little Tensile Stress which is as good as negligible. Hence to make a structure safe and in working condition to take up the Design Loads the structural material must e able to withstand both Tensile as well as Compressive Stresses, now as the Concrete is not strong to withstand the Tensile stress, so some measures is to be taken and it is to be provided with something which will take up the Tensile Stresses developed in Concrete. Due to the above fact A Structural Member such as Column, Beam, Slab etc are not made of Plain Concrete, instead it’s Reinforced with Steel embedded in it, which take ups the Tensile Stresses developed.

### Why Steel is Used As Reinforcement?

Due to the change of temperature the Concrete Expands and Contracts, and the material used for Reinforcing will also expand and contract due to the change of temperature, depending upon their Co-efficient of Volumetric Expansion. If the change of Volume of Concrete and embedded Reinforcement will not be of same amount the at the surface of contact between Concrete and Reinforcement Differential Stresses will develop hence crack will develop and will cause failure of the structure. It is experimentally found that the Co-efficient of Expansion of Concrete and Steel is almost same, hence due to the change of temperature No Differential Stresses will Develop, hence No Cracks, and No Failure, this is the main reason why steel is used as Reinforcement.