CEMENT HYDRATION IN THE PRESENCE OF NANO MAGNESIUM OXIDES WITH CONTROLLED REACTIVITY

摘要

In order to effectively compensate for bulk shrinkage of cement systems, the reaction of expansive additives must be regulated taking into account the development of cement hydration. In this study, nano-MgO particles (NM) with controlled reactivity were added to a cement system. The reactivity of NM was regulated via heat-treatment and the cement systems were investigated using isothermal calorimetry. Our results showed that increase in heat-treatment temperature resulted in coarsening of the NM and retardation of the NM reaction. We demonstrated that the addition of NM, heat-treated at low temperature, to a cement system caused significant reduction in the induction period compared to the reference system without NM. Controlling the reactivity of NMs might be a promising method in designing zero-shrinkage cement systems.