Ceramics-Silikáty 50 (2) 106-114 (2006)

HYDRATION AND MICROSTRUCTURE OF BINDER COMPOUNDS CONTAINING C₂AS AND C₂S SYNTHESIZED BY SOL-GEL METHOD

M. Dováľ, M. Palou, V. Kovár

Sol-gel method has been used to synthesize the nano particles of C₂AS and C₂S. These cement phases prepared by solid-state reaction at high temperatures are hydraulically latent or less active. After heating at 600°C, they were calcined at 900°C and 1100°C to obtain crystals of C₂S and C₂AS respectively. Binder compounds in the framework of C₂AS–C₂S–C₄A₃S–CS–C system were prepared using C₂AS and C₂S synthesized via sol-gel process. Samples showed better hydraulic activity when comparing it with the system, where pure minerals were used. The hydration of this system leads to coexistence of two crystallohydrates of gehlenite hydrate and ettringite, which were originated by primary and secondary reactions. Gehlenite hydrate as well as ettringite were stable.

Keywords: Sol-gel method, Hydration, Gehlenite hydrate, Ettringite