Expansive and shrinkage-compensated cements

摘要

A cement comprises (a) at least one silicate of the type present in Portland cement and having the properties of an hydraulic cement and (b) a stable calcium aluminosulphate in the form of a ternary compound (CaO)4(Al2O3)3(SO3) component (a) being present in such proportion that the cement is an hydraulic, Portland type cement and component (b) being present in such proportion that in the presence of CaO and CaSO4 it will compensate for at least a substantial part of the drying shrinkage of concrete produced by admixing the cement with mineral aggregate and water. The cement is prepared by burning a mixture of a source of CaO, SiO2, Al2O3 and SO3 at a temperature not exceeding 2900 DEG F.