Mechanism of hydration reactions in the system C4A3SCSCaOH2O referred to hydration of sulphoaluminate cements

Reaction scheme and mechanism of hydration reactions in the subsystems: (1) C4A3S + H2O; (2) C4A3S + CSH2 + H2O; (3) C4A3S CSH2 + H2 O, were investigated by X-ray diffraction and thermic methods. Crystallization of the hydration products mass proportion of solid phases to water = 1:10) in the subsystems (1) and (2) occurred according to JMAJK mechanism with a typical sigmoidal course of hydration reaction. Mechanism of hydration reaction in the subsystem (3) depended on the stoichiometry of the starting system.