Advances in self-healing engineered geopolymer composites: mechanisms, materials, and environmental perspectives

This review presents the behavior and competence of self-healing engineered geopolymer composites for sustainable construction and mining industry. Self-healing materials can repair cracks automatically and restore their mechanical properties. They use methods inspired by natural healing, such as encapsulated healing agents, hollow fibers, mineral admixtures, and microbial activity. Fly ash, metakaolin, and ground granulated blast furnace slag are widely used precursors for engineered geopolymer composites. Biological agents such as Sporosarcina pasteurii and Bacillus subtilis promote CaCO₃ precipitation to seal microcracks. Fibers and shape memory materials enhance crack closure and improve durability. Self-healing coatings and waste-based composites provide environmentally friendly solutions for infrastructure repair. Life cycle and environmental impact assessments show that self-healing geopolymers reduce long-term maintenance and improve service life but may increase energy and material burdens during production. This review summarizes recent research on mechanisms, materials, curing conditions, and performance evaluation of self-healing geopolymer composites. It highlights strategies to optimize healing efficiency and mechanical strength. The findings offer insights for sustainable design of durable, smart, and resilient construction materials.