Evaluation of fly ash-based geopolymer concrete incorporating coarse and fine recycled aggregates

Geopolymer Concrete (GC) is emerging as a promising material due to its lower carbon footprint compared to conventional Portland Cement (PC) concrete. One of the ways to further enhance the sustainability of GC is by incorporating Recycled Aggregates (RA). This study focuses on evaluating the performance of GC made with Coarse Recycled Aggregate (CRA) and Fine Recycled Aggregate (FRA). The mechanical property in terms of compressive strength and long-term durability properties, such as the Capillary Suction Test (CST), Initial Surface Absorption Test (ISAT), and acid attack test, were evaluated for all GC mixes. Ultrasonic Pulse Velocity (UPV) test and the electrical resistivity test, have also been done on all GC mixes. The results show that FRA beyond 25%, along with 50% CRA, is having an adverse impact on the long-term durability properties of GC. The GC mix with a combination of 50% CRA and 25% FRA shows at par compressive strength and electrical resistivity values relative to the Natural Aggregates (NA) GC. The findings from this study are expected to provide valuable insights into the optimal use of RA in GC and contribute to the broader goal of developing sustainable construction materials.