Mechanical Properties, Self-Healing Characteristics, and Chloride-Ion Penetration Resistance of Cement-Free Composites Incorporating Aluminosilicate Material-Based Capsules

This study targets lower CO2 emissions by developing cement-free alkali-activated composites made from industrial by-products (fly ash and blast furnace slag). The researchers added aluminosilicate material-based capsules (AMCs) made from a mixture of fly ash, blast furnace slag, and ferronickel slag powder, then experimentally tested durability, mechanical properties, self-healing characteristics, and microstructure. They report that adding 10% AMC led to compressive-strength recovery of 112–118% (about 10% higher than the control). They also report a 79.4% improvement in 28-day resistance to chloride-ion penetration, reaching the ASTM C 1202 “very low” permeability criterion. Overall, the authors conclude these cement-free self-healing composites are a viable construction alternative and that recycling industrial by-products supports sustainability goals.