68 / 2022-04-10 10:44:40

Effect of grain size on the prehydration and hydration kinetics of calcium sulfoaluminate clinker

CSA cement；Prehydration；Fineness；Ye'elimite；Anhydrite

The prehydration of cement when it was exposed to moisture in the air has a significant impact on the final hydration activity and mechanical properties of cement. Due to the higher content of aluminate phases, prehydration is more likely to happen on calcium sulfoaluminate (CSA) cement than on ordinary Portland cement (OPC). In this paper, the effect of particle size on the prehydration and hydration kinetics of CSA cement was investigated. Three kinds of sulfoaluminate cement clinkers with different particle sizes ranging from 26.62 to 6.04μm were prepared by extending the grinding time from 10 to 100 mins. The mineral phase composition of CSA cement with different particle sizes under various humidities was quantitatively analyzed at 0, 7, 28, and 90 days by thermal gravimetric analysis, X-ray diffraction, and isothermal calorimetry. The micro-structures of prehydrated and hydrated CSA cement were analyzed by environmental scanning electron microscopy and mercury intrusion porosity measurement. The results show that the prehydration of CSA cement decreased the compressive strength and reduced the activity of cement hydration.