Abstract
•Drying and autogenous shrinkage of various slag replacement levels are presented in this paper.•Slag, cement fineness, and shrinkage reducer admixture were used to evaluate length change.•Increase slag replacement in ternary mixtures reducelength change up to 360 days.•Decreasing the fineness of blended silica fume cement appears to decrease free shrinkage.
Laboratory experiments were conducted to investigate the effect of ground granulated blast furnace slag (GGBFS) replacement on the length change of high-performance concrete (HPC). Nine concrete mixtures at w/cm ratio of 0.33 were cast using two silica fume blended cements of different fineness and two sources of GGBFS at three levels of GGBFS replacement (25%, 35% and 50%) as well as the use of a shrinkage-reducing admixture (SRA). The length changes due to autogenous and drying shrinkage were lower for the 50% and 35% GGBFS replacement as well as by use of a shrinkage reducing admixture compared to the mixture with 25% GGBFS replacement. Furthermore, the total drying shrinkage of all the concrete mixtures tested were in compliance with the 400 microstrain shrinkage limit specified for low-shrinkage concrete in the Canadian CSA A23.1 standard. The test results have also shown that while increased fineness of the silica fume blended cement increased the compressive strength of concrete, it also resulted in increased drying shrinkage with increased cracking potential.