Investigating the Durability Characteristics of Brick Fired Rice Husk Ash as Sustainable Material for Fly Ash Based Geopolymer Concrete

This study investigates the utilization of brick kiln rice husk ash (BKRHA), a silica-rich agricultural waste by-product from clay brick production, as a partial replacement for fly ash (FA) in geopolymer concrete (GPC). The research evaluates the effects of incorporating BKRHA (10%, 20% & 30% by mass) alongside FA and varying concentrations of sodium hydroxide (10M and 12M) in alkali activators to evaluate the durability performance of GPC. Parametric characterization confirmed the pozzolanic potential of BKRHA. Results reveal that the 10% BKRHA replacement significantly improved durability properties by reducing water absorption by 2.7%, water penetration reduction by 6.2%, increasing post-fire compressive strength by 28.96%, and decreasing chloride ion penetration by 25.23%. Acid resistance was also enhanced, with strength loss reductions of 13.1% at 90 days and 2.6% at 180 days. These findings optimized BKRHA with 10% viability as a sustainable and durable additive in FA-based geopolymer concrete.