Hydration mechanism and kinetic response of a C4A3$-C2S binary system

Abstract

The physical properties of C4A3$-C2S (ye´elimite-belite) clinker system will change with the proportion of C4A3$ or C2S, but the effect of mineral proportion change on hydration mechanism is not systematic and unclear. The C4A3$-C2S binary system was established by experiments, and its hydration process was characterized. The kinetic response of C4A3$-C2S binary hydration system was studied by Kondo model. The results showed that the change of design mineral ratio directly affects the hydration process and the hydration mechanism. The experiment and analysis show that when the design mineral ratio of C2S was lower than 65 wt%, the dominant factor of hydration was mainly controlled by nucleation mechanism (The hydration acceleration period is particularly significant), and when the ratio of C2S was higher, it would be controlled by diffusion mechanism. The precise value of the boundary reaction control is between 65 wt% (design mineral ratio of C2S) to 75 wt%. Only when the hydration kinetics of the binary system is controlled by the diffusion mechanism, the CH product can be stably crystallized. The classical Kondo model is suitable for the C4A3$-C2S hydration system.