Mitigation of drying shrinkage in alkali‐activated reactive powder concrete through copper‐coated microwire steel fibers

Abstract This study investigated the drying shrinkage in alkali‐activated ground granulated blast furnace slag (GGBFS)‐based reactive powder concrete (AARPC) and evaluated the efficacy of copper‐coated microwire steel fibers in minimizing drying shrinkage. Three different mix designs with varying liquid ratios were developed and fibers were incorporated into each AARPC mix at different volumetric ratios. The drying shrinkage of the AARPC was investigated over a duration of 112 days under the drying at 23 ± 2°C with a relative humidity of 50 ± 2%. Drying shrinkage increased with the increase in the liquid ratio in the AARPC mixes without fibers. Incorporating fibers into the AARPC resulted in a substantial reduction in the drying shrinkage. The effectiveness of reducing drying shrinkage improved with an increase in fiber content. Fibers significantly attenuated drying shrinkage of AARPC by up to 51% when 2.4% of microwire steel fibers were used.