The average out-turn of first class bricks in clamp burning is about

The workability of cement concrete can be improved by

According to Indian standard specifications, the temperature for curing is

The time required for air seasoning of soft wood is

The rapid hardening Portland cement has a

The silicious sandstone which has been subjected to metamorphic action, is called

The calcareour rocks have

The crushing strength of a stone depends upon its

The specific gravity of sandstone is