ABSTRACT
The absolute volume method detailed in ACI 211 is commonly used to proportion the local concrete materials to achieve the desired fresh and ultimate hardened concrete properties. This includes selecting the water–cement ratio, coarse and fine aggregate, cement and supplementary cementitious materials, water, and admixture requirements. The water-to-cementitious materials ratio, is the mass of water divided by the mass of all cements, blended cements, and pozzolanic materials such as fly ash, slag, silica fume, and natural pozzolans. Assuming that a concrete is made with clean sound aggregates, and that the cement hydration has progressed normally, the strength gain is inversely proportional to the water–cementitious ratio by mass. The water–cementitious ratio (W/CM) will govern the permeability or watertightness that is necessary for preventing aggressive salts and chemicals from entering the paste pore system and causing deleterious effects in the concrete or reinforcing steel.
