Physical, strength, durability and microstructural analysis of geopolymer concrete: a review

Purpose This study comprehensively reviews the physical, mechanical, durability and microstructural properties of geopolymer concrete (GPC) to highlight its suitability as a sustainable alternative to ordinary Portland cement (OPC) concrete. Design/methodology/approach An extensive analysis of literature from prominent scientific databases was conducted to synthesize findings on GPC. The review focuses on the influence of key parameters, including aluminosilicate precursors, alkaline activator composition and concentration and curing conditions, on the material’s performance. Findings Ambient-cured blends of fly ash and ground granulated blast-furnace slag achieve compressive strengths exceeding 60 MPa while cutting CO2 emissions by roughly 80% compared to OPC. GPC exhibits up to 50% less strength reduction under prolonged sulfuric-acid exposure and develops over 93% of its 28-day strength within seven days when thermally cured, with a one-hour treatment at 90 °C boosting strength by as much as 56%. Microstructural studies reveal a dense, cross-linked aluminosilicate gel matrix that impedes the ingress of aggressive ions, underpinning superior resistance to freeze–thaw cycling, acid attack and fire exposure. However, the high variability of precursor materials and the lack of standardized codes remain significant challenges for standardization. Originality/value This review offers a comprehensive assessment of GPC, bridging a gap in the existing literature by integrating recent findings on both material properties and structural performance. It provides critical insights for researchers and practitioners, underscoring GPC’s potential to significantly reduce the environmental impact of construction while achieving structural integrity comparable to or superior to that of OPC.