Comprehensive assessment of geopolymer concrete mechanical and environmental performance with glass cullet fine aggregates

Abstract

Despite its established reputation and extensive testing as an alternative to conventional cement, geopolymer continues to heavily rely on natural aggregates. The disposal of waste glass presents a significant global challenge as it constitutes a substantial portion of solid waste. This study investigates the application of geopolymer mortar, wherein waste glass cullet serves as the principal component for fine aggregate. Two distinct curing methods, namely ambient and elevated temperatures, were employed to evaluate the mechanical properties of the material in accordance with standards. An optimal aggregate-to-binder ratio of 1:2.5 was determined to achieve suitable workability for in-situ casting applications. Following a 28-day curing period, the geopolymer mortar underwent testing for compressive and tensile strength, bringing acceptable results at 46 MPa and 2.8 MPa, respectively. Additionally, the study examined the relationship between compression and tension characteristics of geopolymer mortar and, through regression analysis, established correlations that accurately predicted data from other published works. Furthermore, the carbon footprint of geopolymer was compared to that of ordinary Portland cement (OPC) concrete, with geopolymer demonstrating the potential to significantly reduce the environmental impact of cement manufacturing, saving 27.76% of the carbon footprint per m3 in comparison to OPC. This study emphasizes the strong mechanical qualities of geopolymer products, which give them a great probability of being employed in industry and creating a new market for waste materials through the usage of by-products.