A Study on the Usability of Red Mud as Activator of Alkali-Activated Cementless Binder

알칼리활성화 무시멘트 결합재의 촉진제로서 레드머드 활용에 관한 연구

The enormous quantity of 'red mud' discharged by industries producing alumina from bauxite represents an environmental and economical problem. As it is mainly composed of $Fe_2O_3$, $Al_2O_3$, $SiO_2$, CaO and $Na_2O$, it is thought that using red mud as a construction material is an effective way to consume such a large quantity of alkaline waste. Therefore, the purpose of this study is to investigate usability of red mud as an solid composite alkali activator into cementless binder mixture system instead of the liquid water glass or caustic soda. As a results, it were found that the alkali-activated cementless blended binder paste based blast furnace slag using red mud had almost integrated and very compacted structure, which was believed to be the physical reasons for its high strength similar to that of ordinary portland cement. But the cementless binders, added to the red mud as activator into only the blast furnace slag or fly ash, are no use as cementitious materials due to the unstable hydration strength. to improve this defect was introduced to the red mud mixes together with extra addition of activators such as portlandite and gypsum.