To make ten cubic metre of 1 ∶ 2 ∶ 4 by volume concrete, the volume of coarse aggregates required is

Explanation:

The given proportion 1:2:4 is by volume with 1 part being cement, 2 parts being Fine aggregate and 4 parts being coarse aggregate.

Total wet volume of concrete = 10 m³

Dry volume of concrete should be taken to be 50 % more than its wet volume.

∴ Dry Volume of concrete, V = 1.50 × 10 = 15 m³

The volume of coarse aggregate, = proportion of coarse aggregate × dry volume /total proportion

Or

Volume of coarse aggregate, V_CA = 4 × 15 /(1 + 2 + 4)

V_CA = 8.5 m³

In a similar manner, the volume of fine aggregate and cement required can also be estimated.

V_FA = (2/7) × 15 = 4.3 m³

V_C = (1/7) × 15 = 2.14 m³