Effect of mix design factors on the self-stress-sensing behavior of metakaolin-based geopolymer

The present study investigates the influence of mix design ratios on the self-sensing behavior of geopolymer pastes. The increase in silicate content, corresponding to high alkali content, leads to higher self-sensing, mechanical strength, and lower resistivity. The alterations in mix design ratios result in modifications to the ions in the pore solution and microstructure of the geopolymer, which are accountable for the variations in self-sensing behavior and electrical performance. The study demonstrates a correlation between the sensing coefficient, determined by the changes in resistivity, and the compressive strength and electrical resistivity. Among the mix design ratios, SiO₂/Al₂O₃ ratio is determined to be the most substantial parameter regarding the self-sensing behavior of geopolymer. The findings suggest that geopolymer has the potential for self-sensing applications without the requirement for supplementary conductive fillers or fibers.