Blast Furnace Slag is a by-product of the manufacturing of steel in a blast furnace. Initially, in its molten form, it is diverted to a granulator where it is quenched with water and rapidly cooled to form glassy, non-metallic granules which are silicates and aluminosilicates of calcium. These granules are dried to produce Granulated Blast Furnace Slag (GBFS) and then ground to a suitable fineness to produce Ground Granulated Blast Furnace Slag (GGBFS). When used as a cementitious material in concrete, GGBFS enhances long-term performance and durability characteristics while reducing life-cycle and maintenance costs.