Composition and performance driven mix design methodology for geopolymer mortars

Geopolymers are gaining attention as sustainable alternatives to conventional cement due to their significantly lower environmental impact. However, mix design remains challenging due to the complex interactions between precursors and alkaline activators. This study proposes a composition and performance driven methodology for designing geopolymer mortars (GPM) that integrate key chemical ratios, such as SiO2/Al2O3, water-to-geopolymer solids (W/Gs), Na2O/SiO2 and H2O/Na2O, into a systematic framework. The method enables the rational selection and adjustment of precursor proportions and activator concentrations to achieve target performance metrics, including compressive and flexural strength, workability and water absorption. Experimental validation with oven-cured GPMs confirms the approach’s effectiveness for applications requiring strength and workability. Furthermore, the methodology is adaptable to various material sources and provides a scalable foundation for the broader development of geopolymer concrete. Thus, this work contributes a robust and transferable mix design approach that bridges geopolymer chemistry with practical engineering practice, enhancing predictability and scalability in geopolymer design. Further research is encouraged to expand its application to other precursors, activators, curing conditions and structural applications.