Rheology behavior of one-part alkali activated slag/glass powder (AASG) pastes

Currently, one-part alkali activated materials (AAMs) show promising applications while the rheological characteristics remain unclear. Also, AAMs incorporating waste glass powder (GP) as part of the precursor have potentials for widely use, but their rheology behaviors have been rarely studied. In this study, the rheology behaviors of one-part alkali activated slag/glass powder (AASG) pastes prepared with a solid sodium water glass (Na-WG) as the activator were investigated and compared with those of ordinary Portland cement (OPC) pastes. Meanwhile, other properties of the pastes including microstructure, workability, setting time and compressive strength were also evaluated. The effects of water to binder (W/B) ratio, activator to binder (A/B) ratio, GP content and the addition of admixtures including calcium aluminate cement (CAC) and silica fume (SF) were systemically quantified. The results showed that the plastic viscosity of the AASG pastes were much higher than that of OPC paste with the similar flow value, but the yield stress of OPC paste was much higher when using the same W/B ratio. The plastic viscosity of the AASG paste increased with the increase of A/B ratio. The yield stress and plastic viscosity of the AASG paste decreased with the increase of GP content. The addition of SF was effective in increasing the yield stress and decreasing the plastic viscosity of the AASG paste due to its fine particle size and spherical morphology.