Early-age autogenous shrinkage strain and stress of portland blast-furnace slag cement concrete were determined taking account of the heat of hydration. When moderate-heat cement and low-heat cement were substituted with ground granulated blast-furnace slag, the strain turned into shrinkage under an increase in concrete temperature. This may be attributed to an autogenous shrinkage accelerated by a rapid decrease in pore spaces as a result of ettringite conversion into monosulfate.The autogenous shrinkage was able to be reduced by increasing the SO3 content of low-heat portland blast-furnace slag cement.It was found by the cement paste experiments that the strain reversal was most affected, among characters of the portland blast-furnace slag cement, by the blaine value, degree of substitution and type of the base cement. The autogenous strain stress showed considerable increase at high ambient temperatures (35°C) than at a room temperature (20°C).
