Geopolymer concrete (GC) is a sustainable construction material and a great alternative to regular concrete. GC is a zero-cement material made from a combination of aluminate, silicate and an activator to produce a binder-like substance.

This investigation focused on the effects of wet and dry cycles on the strength and durability of fly ash-based recycled aggregate geopolymer concrete (RAGC). The wet-dry cycles were performed approximately according to ASTM D559 standards.

RAGC specimens with nearly 70% recycled materials (recycled aggregate and fly ash) achieved a compressive strength of approximately 3600 psi, after 7 days of heat curing at 60°C. Although the recycled aggregate is prone to high water absorption, the compressive strength decreased by only 4% after exposure to 21 wet-dry cycles, compared to control specimens that were not exposed to the same conditions. Accordingly, the RAGC material developed in this study can be considered as a promising environmentally friendly alternative to cement-based regular concrete.