Abstract
The construction sector faces increasing pressure to reduce its environmental footprint, particularly from conventional Portland cement concrete. Geopolymer concrete (GPC), utilizing industrial by-products such as fly ash and slag, offers a promising alternative. This study presents a comprehensive cradle-to-gate life-cycle assessment (LCA) of GPC designed for rigid pavement applications, incorporating industrial by-products as full replacement for ordinary Portland cement (OPC). Four mix designs were evaluated: a conventional OPC pavement concrete and three GPC mixes with varying ratios of fly ash and ground granulated blast furnace slag (GGBFS). Environmental impacts were assessed using the ReCiPe midpoint method across 18 categories, including global warming potential (GWP), acidification, and ecotoxicity. The results indicate that GPC mixes reduce GWP by 45–62% compared to OPC concrete, primarily due to the avoidance of clinker production. However, GPC exhibited higher impacts in categories such as human toxicity and freshwater eutrophication, attributed to the alkali activator production. A sensitivity analysis showed that the choice of activator concentration and transport distances significantly influence overall impacts. The findings demonstrate that GPC with industrial by-products is a viable sustainable alternative for pavement construction, but optimization of activator dosage and sourcing is crucial to maximize environmental benefits. This study provides quantitative evidence to support the adoption of geopolymer technology in infrastructure projects, aligning with global carbon reduction targets.
Keywords
Geopolymer concrete, Life-cycle assessment, Industrial by-products, Pavement construction, Sustainability, Environmental impact, Fly ash, Slag