Blended hydraulic cements are produced by intergrinding or blending Portland cement and supplementary cementitious materials or SCM such as ground granulated blast furnace slag, fly ash, silica fume, calcined clay, hydrated lime, and other pozzolans. The use of blended cements in ready-mix concrete reduces mixing water and bleeding, improves workability and finishing, inhibits sulfate attack and the alkali-aggregate reaction, and reduces the heat of hydration.
