Experimental study on the characteristics, rheological factors, and flowability of MK-GGBFS geopolymer slurry

In this study, we investigated the effects of concentration and modulus of alkaline activator, liquid-solid (L/S) ratio, and sand volume fraction on rheological properties and flowability of metakaolin (MK)-ground granulated blast furnace slag (GGBFS) geopolymer slurry (pastes and mortars). The rheological property of geopolymer slurry was consistent with the Bingham model. A decrease in the modulus and the L/S ratio, or an increase in the concentration increased the plastic viscosity of geopolymer paste. The geopolymer pastes with higher plastic viscosity exhibited a lower fluidity. The yield stress of geopolymer paste was negatively correlated with concentration, modulus, and L/S ratio. An increase in the sand volume fraction increased the plastic viscosity and yield stress of geopolymer mortar, and decreased the consistency and fluidity of that. Moreover, the correlation between rheological parameters of the geopolymer mortar and paste, and the relationship between the flowability parameters and rheological parameters of geopolymer slurry were constructed.