Among the key challenges limiting the scalable adoption of geopolymers is the absence of a rigorous material design framework to ensure consistent performance, as their properties are intrinsically governed by the compositionally heterogenous and regionally sourced aluminosilicate precursors. This study introduces a performance-based geopolymer mix design methodology that achieves target mechanical strength across diverse metakaolin sources. Five commercially sourced metakaolins were investigated alongside laboratory-calcined kaolin with fully controlled thermal histories as a reference. Reactive phase contents were comparatively quantified via X-ray diffraction, nuclear magnetic resonance, dissolution test, and inductively coupled plasma optical emission spectroscopy. The results showed that conventional X-ray fluorescence-based design fails to capture precursor heterogeneity, leading to significant strength variability across different precursor sources. By incorporating reactive phase content, adjusting water-to-solid ratio via inert fillers, and particle size refinement into material design, the strength reproducibility markedly enhanced and sensitivity to precursor variability substantially reduced.
Meng et al. (Wed,) studied this question.