Effect of fly ash/activator ratio on strength development of fly ash based geopolymer paste

Activation of fly ash through suitable alkali medium generates geopolymer as a rection product. Although the process seems economical and straightforward, there are multiple parameters those affect the chemical composition and structural features of the geopolymer. Among the process parameters, fly ash (FA) to alkali activator (AL) ratio is one of the major parameters controlling the formation of initial monomer and subsequent cross-linking to produce the aluminosilicate network. In this work the effect of fly ash to alkali activator ratio is taken as the controlling parameter and its effect on resultant geopolymer structure is analysed. Maximum strength was achieved when FA/AL=2.5 was taken and this optimum mix design also produced the higher densification.