Performance optimization of geopolymer mortar blending in nano-SiO2 and PVA fiber based on set pair analysis

Abstract The method of set pair analysis was used to evaluate the comprehensive performance of geopolymer mortar (GM) based on metakaolin and fly ash modified by nano-SiO2 (NS) and polyvinyl alcohol (PVA) fiber, and the design of mix proportion for GM was optimized. According to the experimental results, the addition of the NS and PVA fiber can improve the comprehensive properties of GM. The properties of GM are better when the NS content is 1.5% and PVA fiber content is 0.6%. The comprehensive performance of GM included workability, mechanical properties, fracture properties, and durability, and the typical performance parameters were selected as slump flow, compressive strength, bending strength, fracture energy, loss ratio of compressive strength after cycles of freezing-thawing, and electric flux values. The results show that the weights of each indicator derived from the method of set pair analysis have reduced subjective arbitrariness, improved the evaluation accuracy, and made the conclusions obtained from the set pair analysis method more scientific and reasonable. The method of set pair analysis combines the mechanical properties, durability, and workability of GM blending in PVA fiber and NS to achieve a comprehensive qualitative and quantitative evaluation, which can provide a new method for assessing the comprehensive performance of the GM composites blending in PVA fiber and NS in the future.