A review of the life cycle assessment of geopolymer concrete

Abstract

Geopolymer concrete (GPC) has emerged as a promising alternative to Portland cement concrete (PCC), offering a lower carbon footprint, superior performance, and enhanced resource efficiency. It is synthesized from aluminosilicate industrial byproducts, including fly ash (FA), ground granulated blast-furnace slag (GGBFS), metakaolin (MK), and rice husk ash (RHA). When activated by alkaline solutions, these precursors form a three-dimensional amorphous network, eliminating the need for energy-intensive clinker firing. This review systematically evaluates the life cycle assessment (LCA) of GPC and compares its environmental performance with that of PCC. Several factors strongly influence the LCA outcomes of GPC. Alkaline activators, particularly sodium silicate (Na2SiO3), are identified as primary contributors to global warming potential, human toxicity, and resource depletion. Precursor selection also plays a decisive role. High-calcium materials such as GGBFS yield superior strength with relatively lower impacts, while MK-based systems may result in higher overall burdens due to their elevated Na2SiO3 demand. Curing regimes further affect the sustainability profile, as high-strength mixtures often require high-temperature curing, introducing additional trade-offs compared with ambient curing used in PCC. Moreover, transportation of raw materials, especially regionally constrained components like Na2SiO3 and MK, significantly adds to the environmental footprint. Despite these insights, current studies remain limited, as most LCAs only adopt cradle-to-gate boundaries and overlook use-phase and end-of-life scenarios. This review identifies key research gaps and proposes future directions, including the development of low-impact activators, ambient curing strategies, and integration of durability and circular economy principles into LCA frameworks to advance sustainable GPC deployment.