Hydration properties of ladle furnace slag powder rapidly cooled by air

•Ladle furnace slag, the waste from steelmaking industry can be recycled.•Rapidly air cooled ladle furnace slag is a rapid hardening binder.•Rapid air cooling method prevent expansion of the steel slag.•Rapidly air cooled ladle furnace slag produce hydrogarnet during the hydration. Present research provides a series of research to provide the hydration properties of pulverized rapidly air cooled ladle furnace slag. In aspect of sustainability, recycling slags from steel producing industry is valuable, while only blast furnace slag has been used as a construction material. Since the main obstacle of the slags to be used as a construction materials is expansion of the matrix due to the free-CaO or free-MgO. In this research, using high pressured air, the molten ladle furnace slag was cooled down rapidly, and the crystallization of these harmful components were prevented. Furthermore, because of amorphous phases and chemical composition of C12A7, and β-C2S, the pulverized rapidly air cooled ladle furnace slag showed rapid setting properties. Therefore, in this research scope, the rapid setting properties of rapidly air cooled ladle furnace slag was found.