The influence of steel slag and ferronickel slag on the properties of alkali-activated slag mortar

With the continuous development of industry, a huge amount of industrial wastes have been produced and caused severe environmental problems. In order to reduce the issue caused by industrial waste, in this investigation, 50 wt% ground granulated blast furnace slag (GGBS) replaced by steel slag (SS) or ferronickel slag (FNS) was used to prepare alkali-activated blended slag mortar. Hydration process, strength, autogenous shrinkage, drying shrinkage, pore structure, chloride ion diffusion coefficient and water absorption of mortars were investigated and compared with the same strength level Portland cement (PC) mortar. The results show that the utilization of 50 wt% SS or FNS can prolong the setting time, increase the fluidity and porosity, but decrease the hydration heat, 7 days autogenous shrinkage, drying shrinkage and chloride ion diffusion coefficient of mortar. Compared with PC mortar of the same strength, alkali-activated GGBS-SS mortar or GGBS-FNS mortar possesses relatively lower hydration heat, porosity, water absorption capacity and chloride ion diffusion coefficient. (C) 2019 Elsevier Ltd. All rights reserved.