Autogenous Shrinkage Strain Properties of Portland Blast-furnace Slag Cement Concrete Taking Account of the Heat of Hydration
By Katsuki Harada, Hiromichi Matsushita and Takahiro Goto
Concrete Research and Technology
Vol.14, No.1, Jan 2003 (Issue 31)
- Synopsis:
- 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 stain 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).
- Keywords:
- portland blast-furnace slag cement, autogenous shrinkage, temperature history, ettringite, pore
