The effect of additive compounds on the fresh properties of fly ash-based geopolymer binder

Abstract The utilization of fly ash-based geopolymer serves as a practical alternative to reduce the dependence on cement as a binding element, particularly in concrete construction. The increased viscosity of the geopolymer mixture requires careful evaluation of its effects on the fresh geopolymer’s physical properties, specifically its workability and setting time. This study investigates the impact of additive compounds, including superplasticizer, additional water, and extra cement, alone or in combination, on the initial properties of geopolymer mixtures, specifically geopolymer binders. The findings of workability testing conducted using the mini-slump test, and setting time analysis, performed using the Vicat apparatus, demonstrate that the inclusion of superplasticizer, additional water, and extra cement can either enhance or diminish the physical characteristics of the geopolymer combination. Hence, it is essential to evaluate the utilisation of the geopolymer combination to achieve the most optimal physical characteristics, while also taking into account its potential for on-site application.