How to select the Grade of concrete In beams,columns and slabs??

[Megha syam kumar.k]

I am kindly requesting every member plese guide me.

 

[Dnyan Deshmukh]

To best of my knowledge, grade of concrete is decided base on loads and stresses it carries.
It also depends on the how fast you are going to construct it, faster the construction, the live and dead loads are going to act faster on the concrete and it requires more than desired design strength to accommodate it.

I am not a structural designer, so i might be wrong for whatever i interpreted.