Hydration characteristics of beta-C2S in the presence of some accelerators

beta-dicalcium silicate (beta-C2S) is present in portland cement as belite stabilized by some impurities. The hydration of beta-C2S is similar to that of C3S but with slower rate. Extensive investigation had been done on the effect of CaCl2 as accelerator on the hydration of C3S but meager work had been done on belite (beta-C2S). The aim of the present work is to investigate the effect of some accelerators such as CaCl2, Ca(NO3)(2), Ca(CH3COO)(2) and K2CO3 on the hydration of B2O3 stabilized beta-C2S. The results show that the hydration of pure beta-C2S liberates Ca(OH)(2) up to 28 days which is consumed within 90 days. The hydration products are mainly tobermorite like phase with some CaCO3. On the other side, the effect of accelerators consumes the liberated Ca(OH)(2) and accelerates the hydration of beta-C2S.