Effect of Amount on Expansion Property of MgO-Type Expansive Agent Used in Cement-Based Materials

Abstract

Previous research indicated that the expansion property of MgO-type expansive agent (MEA) strongly depended on the amount. However, the quantitative effect of amount on expansion property of MEA has not been clearly demonstrated. In the present the expansion value of cement paste with 3%, 4%, 5% and 6% MEA calcinated at 850°C and 1200 °C, and then relative expansion value was introduced to investigated the relationship between the mount and expansion of MEA. The results indicated The relative expansion of MEA calcinated at 850°C was relative invariant to curing temperature and proportional increased with the amount ratio. The relative expansion of MEA calcinated at 1200°C proportional increased with curing age, and the increasing rate rose with the amount ratio of MEA and curing temperature.