The hydration processes of high-volume ¯y ash cement paste were investigated by examining the non-evaporable water content,
the CH content, the pH of pore solution and the fraction of reacted ¯y ash, curing at either 20°C or elevated temperatures after an
initial curing at 20°C. The replacement percentage levels of ¯y ash were 40%, 50% and 60% by weight, respectively. The results
revealed that the non-evaporable water content in high-volume ¯y ash cement pastes does not develop as plain cement pastes does,
so it may be improper to apply the non-evaporable water content to evaluate the hydration process in high-volume ¯y ash cement
matrix. The reduction in CH content increases with the progressing of hydration process and varies linearly with the logarithm of
curing age.