Thermal activation of air cooled slag to create one-part alkali activated cement

An environmentally friendly alkali activated cement powder was prepared by the transformation of air cooled slag (ACS), with low reactivity, into high reactive cementitious material. The recycling process was carried out by thermal activation of ACS in the presence of fluxing materials followed by quenching and crushing to produce cement powder with a fixed particle size, yielding alkali activated cement powder, which can react with water like Portland cement. Type and content of fluxing material were investigated in this communication. The results proved that there is no change in the crystalline structure of ACS when it exposed to 1200 °C (with no fluxing materials). Meanwhile, it can convert to amorphous material with a complete vitreous structure in the presence of sodium hydroxide and feldspar. The dissolution/condensation process of the amorphous aluminosilicate initiated after adding water to the prepared cement powder, yielding hardened cement pastes with higher mechanical properties as compared to untreated alkali activated ACS.