Mechanical properties of fabric-reinforced geocomposites in accordance with novel size-independent flexure-test technique

In this paper, two silica-based geopolymer matrix systems reinforced composites were synthesized and fabricated at optimal conditions. The composites contained approximately 40 wt.% of Carbon HTA twill (TohoTenax) and 48 wt.% of advanced S-glass twill (Saint-Gobain, Vetrotex), respectively. The resulting composites exhibited quite high toughness, with the shear stress playing a greater role compared to other ceramic matrix composites. To determine the flexural properties of the composites, a universal testing machine was used under the three-point bending mode. This evaluation was conducted using a novel size-independent technique based on testing specimens at different scales of the sample height (H) to span length (L) ratio. Microstructure analysis of the composites was performed using a scanning electron microscope (SEM). The analysis aimed to assess the effective impregnation and adhesion between the fiber and geopolymer matrix, as well as to identify micro-cracks, which are inborn defects in inorganic matrix composites. The findings presented in this study highlight the potential of the synthesized silica-based geopolymer matrix composites and their applicability in various engineering fields.