Determination of Weights of Ingredients by Absolute Volume Method:

The weight of cement required to produce one cu-m of concrete is found out through this method. The principle of this method is that the volume of compacted concrete is equal to the sum of the absolute volume of all ingredients.

If W = Weight of cement required per cu-m of concrete,

ρ_c = Specific gravity of cement,

ρ_CA = Specific gravity of coarse aggregate,

ρ_FA = Specific gravity of fine aggregate,

ρ_w = Specific gravity of water, and

V = % age of entrained air in concrete. Proportions by weight of material

= Cement: FA: CA: Water

= 1: NFA: NCA: W

The weight of cement could be found out as below:

W₁/P_gP_w + N _HA/P_FA . P_w1 + N_CA W₁/P_CA P_w1 + W. W/P_w + 0.01 V = 1 cu.m

In case some admixtures are used as additional ingredients in mix, then similar terms with respect to WB1 may be added.