2019 Volume 73 Issue 1 Pages 32-37
The quality of cement changes depending on storage condition such as temperature and humidity. In this study, the influence of storage condition on cement characteristics and properties were evaluated. The cement was stored in four conditions which differed from each other in temperature and humidity. Two characteristics were measured：the mass ratio of hemihydrate to gypsum and hemihydrate （ratio of hemihydrate） and the sample’s weight loss up to 500℃, which is not due to dehydration of gypsum. Moreover, the sample’s properties such as compressive strength and setting time were measured. In high humidity condition, cement absorbed moisture resulting in weight loss increase. Because of this, the compressive strength decreased and the setting time was delayed. In low humidity and high temperature condition, the weight loss did not change but the ratio of hemihydrate increased. This caused delay of the setting time. In low humidity and low temperature condition, characteristics and properties did not change.
