Performance of geopolymer concrete for paver blocks in light traffic applications by incorporating granite waste as fine aggregate replacement

Granite stone processing generates significant non-decomposable waste, which can be repurposed in the production of eco-friendly geopolymer concrete (GPC), promoting sustainable construction practices. This study focuses on developing paver blocks by substituting natural aggregates with waste granite (GW) and using fly ash (FA) and ground granulated blast furnace slag (GGBS) as binders for light traffic conditions. Sodium silicate (Na₂SiO₃) and sodium hydroxide (NaOH) serve as alkaline activators at 10 molarity. Two mixes, M1 (420 kg/m³) and M2 (380 kg/m³), were tested with GW substitutions of 0%, 15%, 25%, and 35% for fine aggregates. Mechanical properties, including compressive, split tensile, and flexural strength, were evaluated alongside durability features such as water absorption, ultrasonic pulse velocity, carbonation, and chloride penetration, with assessments of salt attack using magnesium sulfate, sodium sulfate, and sodium chloride. A life cycle assessment (LCA) measured environmental impacts, embodied energy, and CO₂ emissions. Results revealed that replacing river sand with up to 25% GW improved compressive strength by 8.35% and 10.10% for mixes M1 and M2, respectively, while reducing CO₂ emissions by 20.03% and 19.41%.