Hydrothermal Synthesis of Calcium Silicate Hydrates from beta-dicalcium Silicate

Abstract

Beta-dicalcium silicate (beta-C2S) is an important constituent of cement and cement-based materials which are friendly to the enviroment. Hydration of beta-C2S was carried out under hydrothermal conditions at different temperatures from 50oC to 400oC up to 5 days by using two methods to start the hydration reactions at room temperature or at a desired reaction temperature. 7 kinds of hydration products of calcium silicate hydrates (C-S-Hs) were formed from beta-C2S. The stability and formation mechanism of the C-S-H phases were discussed. The effect of two reaction methods on formation of C-S-H phases was also investigated.