Synergistic utilization of blast furnace slag with other industrial solid wastes in cement and concrete industry: Synergistic mechanisms, applications, and challenges

Granulated blast furnace slag (GBFS) is widely used in cement and concrete industries due to its excellent hydration properties. However, there is a huge capacity gap between the steel industry and the cement industry, and hence, the supply of GBFS can hardly meet the demand. At present, few studies have focused on the preparation of cementitious materials with GBFS-like properties, and a detailed summary of the mechanisms is lacking. This review summarizes the physical and chemical properties of GBFS and comprehensively discusses the hydration process in cement. In addition, the synergistic effects between GBFS and solid wastes (red mud, steel slag, gypsum and fly ash) were analyzed in detail. Based on the analysis of this work, there are four synergistic mechanisms among them. Moreover, a method for using solid wastes as raw materials to produce composite GBFS is proposed. It is beneficial to valorize various industrial solid wastes, promote cross-industry cooperation and alleviate the demand of the cement industry for high-quality GBFS. Although it is a theoretically possible method, there are still some problems that need to be solved, such as the lack of uniform quality and environmental standards. This work can provide useful advice for the preparation of composite GBFS.