Improving the Characteristics of Less Active Geopolymer Binders Utilizing Ground Granulated Blast-Furnace Slag under Different Curing Conditions

Abstract

In the current study, the influence of substitution of ground granulated blast-furnace slag (GGBFS) on the characteristics of less active geopolymer binders, including pumice and the waste material produced during the washing process of sand in aggregate industries (waste soil), is investigated. The aforementioned materials were examined individually and in hybrid form. In the hybrid mixes, less-active materials (pumice and the waste soil) were replaced with GGBFS at levels of 25%, 50%, and 75%. The evaluated properties consisted of compressive strength, modulus of rupture, sorptivity, rapid chloride ion migration coefficient, and the content of water absorption. Moreover, the effects of different curing conditions on the properties were investigated. The results indicate that partial replacement of the waste soil and pumice with GGBFS leads to enhanced durability and mechanical characteristics owing to the higher reactivity of GGBFS. The mixture denoted as P25S75 (with 75% GGBFS and 25% pumice) exhibited the best durability properties, surpassing even the S100 mixture (with 100% GGBFS). Substituting the waste soil with GGBFS had a greater enhancing effect compared to the mixtures containing the pumice mixes.