Durability against dry–wet and freeze–thaw cycles of alkali residue-based foamed concrete

Alkali residue-based foamed concrete (A-FC) is considered a highly promising novel material, and it offers the advantages of curbing cement consumption while concurrently mitigating environmental pollution. This study aims to investigate the durability of A-FC. Dry–wet and freeze–thaw cycle tests were conducted to investigate the variation characteristics in the mechanical properties and microstructure of A-FC. The mechanical and pore structure parameters of A-FC were determined from compression tests and scanning electron microscopy analyses. The findings reveal that minimal changes were observed in the mass, volume, and compressive strength of the specimens following dry–wet and freeze–thaw cycles. This underscores the exceptional durability of A-FC, and shows it to be highly suitable for a range of engineering application. Dry–wet cycles increased the brittleness of A-FC, whereas freeze–thaw cycles yielded the opposite outcome. Throughout the dry–wet and freeze–thaw cycles, the combined effects of temperature stress, ice swelling pressure, and seepage pressure collaborated to fracture the vulnerable pore, giving rise to the formation of cracks; as the deterioration continued, both the compressive strength and durability coefficient decreased.