Effect of temperature on C–S–H gel nanostructure in white cement

Abstract

Different ages of white cement pastes hydrated at 100 % RH and 25 or 65 °C were characterised with 29Si MAS NMR spectroscopy. The findings showed that raising the curing temperature from 25 to 65 °C accelerated hydration of the belite phase considerably, inducing a sixfold rise in its one day degree of hydration, while alite phase hydration grew by a factor of only 1.5 in the first day. Moreover, the C–S–H gel formed at the higher temperature had a longer mean chain length and a higher initial uptake of Al3+. Lastly, curing at a higher temperature stabilised only one crystalline aluminate phases, calcium hemicarboaluminate.