Enhancing self-healing efficiency of concrete using multifunctional granules and PVA fibers

Self-healing concrete can prolong the lifespan of structures by sealing cracks. This study assessed the self-healing efficiency of combined multifunctional self-healing granules (SHGs) and PVA fibers under different curing conditions in self-healing concrete. Microstructure analysis of self-healing specimens and products was conducted to reveal the self-healing mechanism. Compared to using SHGs or PVA fibers alone, the synergistic effect of SHGs and PVA fibers improved the compressive strength recovery rate, permeability coefficient recovery, and surface crack closure effect. PVA fiber inhibited crack propagation and provided attachment points for self-healing product deposition, while SHGs released self-healing agents and produced hydrated calcium silicate, calcium carbonate, and magnesium hydroxide to repair cracks. The addition of SHGs also increased the utilization of carbon dioxide and ions in seawater, thereby decarbonizing the environment and reducing the erosive effect of seawater ions.