Effect of Green and User-Friendly Activators on the Compressive Strength of Alkali-Activated Slag Mortar

Portland cement (PC) is a traditional binding material used in cement-based composites. However, the increasing detrimental effect of PC on the environment due to its production process has called for a need to use other times of binders in cementitious composites. The usage of alkali-activated binders has gained attention recently due to the total elimination of the PC as a binder. Alkali-activated binders are obtained by activating aluminosilicate precursors with alkalis. However, the high embodied energy coupled with the corrosive energy associated with the conventional activators used has limited the large-scale application of these types of binders. Therefore, this study was carried out to investigate the effect of green and user-friendly activators on the compressive strength of alkali activator mortar. The activators used are sodium carbonate, lime, and silica fume, and these activators are used solely and as binary activators. Results showed that structural grade strength can be achieved at 28 days with the use of these green and user-friendly activators. However, mortars activated with these activators exhibit lower early strength.