Geopolymers from construction and demolition glass waste: a review of technological trends and sustainable applications

Recycled glass from construction and demolition waste has emerged as a promising precursor in geopolymer production, offering a sustainable alternative to traditional Portland cement. This review synthesizes recent technological advancements and environmental benefits associated with glass-based geopolymers. Key findings reveal that incorporating recycled glass enhances compressive strength, durability, and thermal resistance, while significantly reducing carbon emissions compared to conventional cementitious materials. However, challenges remain due to the variability in glass chemical composition, which can negatively impact geopolymerization processes, leading to inconsistencies in the final product’s performance. The review further explores how the integration of additives such as fibers, silica fume, and nanoparticles can mitigate these challenges by improving mechanical properties, including tensile and flexural strength, and enhancing chemical stability. These enhancements are critical in extending the potential applications of geopolymers in aggressive environments. Additionally, the use of recycled glass in geopolymer matrices contributes to significant waste valorization, effectively lowering the demand for virgin raw materials and reducing the environmental burden associated with landfill accumulation. The reduction in energy consumption, particularly by avoiding the high-temperature processes typical of Portland cement production, further amplifies the sustainability of glass-based geopolymers. Despite these environmental and mechanical advantages, technical barriers, including the need for more effective glass sorting and pre-treatment methods, continue to limit widespread adoption. Future research should focus on optimizing geopolymer formulations, improving processing techniques, and scaling up production processes to meet the demands of industrial-scale applications. This review concludes that recycled glass-based geopolymers offer a viable and eco-friendly solution for the construction industry, providing a key pathway toward more sustainable building practices and reducing the overall environmental footprint of construction materials.