PERFORMANCE EVALUATION OF WASTE GLASS POWDER IN AMBIENT-CURED GEOPOLYMER CONCRETE

Abstract

This research investigates the feasibility of utilizing finely ground waste glass powder (GP) as a partial substitute for Ground Granulated Blast Furnace Slag (GGBS) in geopolymer concrete. Five concrete mixtures were developed with GP replacement levels of 0%, 5%, 10%, 15%, and 20% by total binder weight. All mixing and specimen preparation followed ASTM C192/C192M, while aggregate properties conformed to ASTM C33/C33M. Compressive strength (ASTM C39/C39M) and flexural strength (ASTM C78/C78M) were evaluated at 7 and 28 days of ambient curing. Acid resistance (mass loss) was determined according to ASTM C267 after 56 days of immersion in 5% Sulphuric acid. The results revealed that replacing GGBS with up to 15% glass powder improved both mechanical and durability properties, with the GP15 mix achieving a 28‑day compressive strength of 56.8 MPa and flexural strength of 6.1 MPa. Beyond 15% replacement, strength and acid resistance declined due to dilution of reactive calcium. The study confirms that 15% glass powder is the optimum replacement level, offering a sustainable alternative for geopolymer concrete production.