Steel + Concrete = safe therefore we use steel in concrete to get more strength.
If Only Steel = We can’t support it to use steel for all construction works.
If We use only Concrete in Construction = its too dangerous for building construction work.
Proof
Concrete is weak in tension But it’s strong in Compression, therefore we use steel in concrete to make it strong in tension. But remember that steel is also good in compression because steel has more strong from concrete. Actually the steel quantity is used less from concrete in construction works.
And its therefore weak in compression that’s we use the X – Section in concrete like in column so the cross-section area is already small therefore its weak in compression if the high loads come on the steel so it cross-section area has a chance to become buckling. Other hand concrete has a large Cross Section, therefore, its Strong in Compression.
For More Info Watch This Video