Ceramics-Silikáty 19, (2) 97 - 104 (1975)

Hydrothermal treatment of the main Portland cement minerals 3CaO.SiO₂ and β-2CaO.SiO₂ at above 120 - 130 °C produces C₂SH(A) as the main hydrosilicate phase, apart from Ca(OH)₂ liberated by the reaction. Under hydrothermal conditions C₂SH(A) reacts fairly readily with β-quartz since already a 2-hour reaction at 175 °C (9 atm . g) yields CSH(I) as the main hydrosilicate phase of the system in question. In the subsequent process stage, the above phase is partially transformed to 11 Å tobermorite (5CaO.6SiO₂.5H₂O). After a 72-hour reaction, C₂SH(A) could no longer be identified in the system.