Drying shrinkage of one-part alkali-activated slag concrete

Abstract

The aim of this study was to evaluate the drying shrinkage of one-part alkali-activated slag concrete (AASC) for up to 180 days that is influenced by mix design parameters. A total of 24 mix designs for AASC and one for OPC concrete were made and cured in two different environments. The impacts of mix design parameters including water to binder ratio, silica fume to binder ratio, alkaline activator to slag ratio, and two curing regimes, in water and sealed plastic bag, on drying shrinkage were investigated, using experimental tests and SEM analysis. The results showed nearly 75% of the 180-day shrinkage was reached within 20 days. The results also revealed that the addition of silica fume considerably reduced drying shrinkage magnitude. AASC samples cured in sealed plastic bags resulted in at least a 5.9% increase in drying shrinkage. The maximum drying shrinkage was observed in a mix design containing the highest water to binder ratio and zero silica fume content regardless of curing type. The results indicated that the application of silica fume as a co-binder led to a considerable reduction in the drying shrinkage.