Influence of temperature on phase assemblages of belite-ye'elimite cement
Natechanok Chitvoranund, Barbara Lothenbach, Diana Londoño-Zuluaga, Frank Winnefeld, Karen Scrivener
Abstract
This paper studies the effect of temperature on the phase assemblages of belite-ye'elimite cement. A comparison is made between thermodynamic modelling and experimental data at 28 and 180 days of hydration at 5, 20, 40, and 60 °C. The fast reaction of ye'elimite and anhydrite resulted in the formation of ettringite, monosulfate and Al(OH)3 during the first day. The slow reaction of belite led to important changes in phase assemblages. The formation of C-S-H was predicted and observed at high belite degree of reaction. Siliceous hydrogarnet was observed experimentally only at 60 °C. The strätlingite content decreased at elevated temperatures. C-S-H and strätlingite were observed to be finely intermixed with the AFm phases. The belite reaction contributes to additional strength after 28 days of hydration. The relationships between the compressive strength and bound water or calculated porosity were found but the effect of temperature is still unclear.