Question

In R.C.C slabs only iron rods are used but not of any other metal because
(A) it has more ultimate strength
(B) they are cheap
(C) elasticity is more
(D) the coefficient of expansion of concrete and iron are equal

Answer 1

Hint:Use the information that we use rods which are made up of useful material which does not produce any tension effect in the R.C.C because R.C.C is stronger in compression but weaker in tension. The certain amount of tension may break the R.C.C, and we cannot obtain the desired result.

Complete step by step answer:
The full form of R.C.C is roller-compacted concrete. We know that the R.C.C has a wide range of applications in construction, like we use R.C.C in rod construction, in construction of a dam, in beams, etc. It has a wide range of applications because it gives a high production rate and reduces construction time. To strengthen the R.C.C, we use rods, the selection of rod based on the properties of the rod as well as R.C.C.We know the R.C.C is very strong in compression, but it cannot withstand the tension effect. So the rod which does not produce any tension effect is desirable for the R.C.C. Generally iron rods are used in the R.C.C because the elastic limit of an iron rod is more. They do not produce tension up to a large amount inside the R.C.C.
Therefore, in R.C.C slabs, only iron rods are used but not of any other material because the elasticity of the iron rods is high, and option (C) is correct.

Note: Remember the properties of the iron because according to its properties, we use iron in the R.C.C slab and also remember the properties of R.C.C. We cannot use other materials because they may produce tension effects in the R.C.C. slab, and it may result in the breakdown of concrete.