Effects of fiber hybridization on mechanical properties and autogenous healing of alkali-activated slag-based composites

This paper investigated the effects of hybrid fiber-reinforcement on the mechanical properties and autogenous healing ability of alkali-activated slag (AAS) composites. Three composites with varying quantities of fibers were investigated using a comprehensive set of experiments including mechanical behavior characterization, autogenous healing measurement, and microscopic characterization of healing products were performed. The experimental results showed that for the same total fiber volume fraction, the AAS composite using hybrid PE-PVA fibers achieved higher tensile strain capacity than the mixture using only the PE fibers. In terms of crack width reduction, stiffness restoration, and tensile recovery, the composite reinforced by hybrid PE-PVA fibers showed superior healing performance than that of the composite reinforced with only PE fibers. Even at a small volume fraction of 0.25%, the PVA fibers had an influence on the nature of the healing products.