THE EFFECT OF DIFFERENT DESIGN RATIOS ON THE COMPRESSIVE STRENGTH OF GEOPOLYMER CONCRETE: A PARAMETRIC STUDY USING THE TAGUCHI METHOD

Abstract

This paper presents the influence of numerous limits on compressive strength of fly ash-based geopolymer concrete mixtures optimized by Taguchi method using Minitab program. The major goal is to find the optimal ratios that may give the greatest compressive strength of geopolymer concrete. A total of twenty fife mixtures of geopolymer concrete with fife mixtures of normal concrete were assessed considering the effect of inclusion of Alkali-Activator to binder ratio (AA/B), NaOH concentration (M), Influence of Na₂SiO₃ to NaOH ratio (SS/SH) and effect of binder content (B). Different molarities was used in this study: 8, 10, 12, 14, and 16. Flay ash by way of waste material is used in ratios of (15, 17.5, 20, 22.5, and 25) % and substituted via 90 % of ordinary Portland cement to output the geopolymer concrete. Also, sodium silicate to sodium hydroxide are utilized in ratios of 1, 1.5, 2, 2.5, and 3. The alkali activator was made using sodium silicate, sodium hydroxide, and water in ratios of (0.3, 0.35, 0.4, 0.45, and 0.5). One type of locally crushed coarse aggregate was used instead of normal coarse aggregate that has sizes of 19 mm, as well as, fine aggregate. The examined mechanical property is characterized by compressive strength. The outcomes specify that the geopolymer concrete exhibits The highest compressive strength has been reached when the alkali-activator to binder ratio equal to 0.45, NaOH concentrations equal to 16, Na₂SiO₃ to NaOH ratio equal to 1 and binder content reached to 25 %. Also, the result showed that the compressive increases as the curing age increases. Moreover, scanning electron microscopy was evaluated to show the geopolymer concrete microstructure.