Mechanical characteristics and developing a compressive stress–strain model of geopolymer concrete

Geopolymer concrete (GPC) is a new eco-friendly material that can substitute for traditional cement-based products. The chemical reaction of aluminosilicate precursors with alkali activators produces these materials, giving high strength durable, and minimizing carbon emissions. Besides, geopolymers display remarkable mechanical properties, offering high compressive and tensile strength, and are exceptionally fire and corrosion-resistant. Due to its durable and versatile properties, GPC shows promise as a wise choice for sustainable construction. In civil engineering, these materials can be employed in several applications, particularly buildings, bridges, roads, and other similar infrastructure projects. This paper presents the characteristics of GPC in terms of compressive strength, tensile strength, elastic modulus, and stress–strain. The equations used to measure stress–strain, modulus of elasticity, and tensile strength of GPC samples were collected from different literature sources. To assess the performance of the collected formulas, comparisons were implemented with the experimental data. It has been proven that the corresponding stress–strain relationships recommended by the standards of Ordinary Portland Concrete (OPC) do not accurately express the stress–strain behaviour when applied for GPC. Also, the results showed that when having similar compressive and tensile strength, the elastic modulus of GPC is lower than that of OPC. Therefore, a constitutive model is proposed, describing geopolymer concrete complete stress–strain behaviour. The modified equations obtained in this study can provide relatively accurate predictions for the mechanical behaviour of GPC.