Shrinkage of high-strength calcium sulfoaluminate cement concrete with impact of pre-soaked lightweight aggregate internal curing

Abstract

The effect of internal curing using pre-soaked lightweight aggregate in high-strength calcium sulfoaluminate cement concrete on shrinkage and internal humidity was investigated. Five mixture proportions with induced internal curing water (absorbed by lightweight aggregate) to cement (wIC/c) ratios of 0, 0·03, 0·06, 0·09 and 0·12 were used in the experiments. The experimental results show that the decrease of internal humidity is gradually reduced with an increase in wIC/c ratio. Accordingly, both autogenous and drying shrinkage of concrete also gradually decrease with an increase in wIC/c. Internal curing cannot eliminate the autogenous shrinkage completely because part of the autogenous shrinkage develops within the humidity-saturated stage for early-age concrete.