Effect of chlorine bypass system dust on fresh state properties and strength development of high-volume blast-furnace slag mortar

In this study, chlorine bypass system (CBS) dust is proposed as a new alkali activator and the feasibility of applying CBS dust for high-volume blast-furnace slag (HVBFS) mortar is confirmed. CBS is a dust-collecting system for the cement-manufacturing process that collects dust with chloride and alkali. In general, most of the collected CBS dust in South Korea is wasted. As an effort to reduce waste and incidental costs during the cement-manufacturing process, in this study, cement powder was replaced by CBS dust as an alkali activator for blast-furnace slag. From the experiment of HVBFS mortar activated with various CBS dust proportions, favourable results were observed in terms of fluidity and air content when the CBS dust replacement exceeded 5%. Additionally, regarding strength development, CBS dust was successful as an alkali activator for the latent hydraulic reaction of blast-furnace slag. Therefore, when CBS dust was used as a 5% replacement, its efficiency as an alkali activator in which a large amount of blast-furnace (HVBFS) slag was substituted under the research conditions in this study was confirmed in terms of fluidity and strength development performance.