High Strength Geo-ploymer Concrete with Crumb Rubber Tyre Aggregates Performances and Sustainability

Given the increasing worries regarding climate change, waste management, and carbon emissions [1–3], geopolymer concrete (GPC), which is produced from alkali-activated aluminosilicate sources such as fly ash is becoming a promising substitute for traditional Portland cement concrete (PCC) because of its lower environmental impact and similar strength. [4,5]. At the same time, researchers are investigating the incorporation of crumb rubber aggregates into concrete to minimize waste in landfills and improve energy absorption characteristics [6–9]. While the inclusion of crumb rubber enhances flexibility, shock resistance, and sustainability, it usually leads to decreases in compressive, tensile, and bending strength because of weak interfaces among the rubber and binder, as well as increased porosity [10–12]. This study explores the performance of high-strength GPC with different proportions of crumb rubber, evaluating its mechanical and durability characteristics under standard testing conditions [13,14]. The findings indicate a compromise between strength and sustainability, suggesting that the optimal rubber content in geopolymer mixes can yield eco-friendly, cost-effective, and functional concrete suitable for non-structural or low-load applications, such as paving blocks and pathways [15].