Investigation on Hydration of Two Portland Cements with Different C3S Content

摘要

The hydration process of two Portland cements with C3S content of 55.4% and 64.6% respectively at the water to cement ratio of 0.5 within 360 days were investigated by using X-ray diffraction, differential scanning calorimetry, backscattered electron imaging, energy dispersive X-ray analysis and non-evaporable water content measurement. The results show during the hydration process of the Portland cement with high C3S content more Ca(OH)2 is produced, and the degree of hydration of this cement measured by backscattered electron image analysis is higher than that of the cement with low C3S content. But by using the traditional non-evaporable water content measurement, the degree of hydration of high CjS cement is lower than that of the low C3S cement in the later ages. The microstructure of two cement pastes can be observed clearly by using the backscattered electron imaging. At 360 days, even if in the high C3S cement paste, there are still some unhydrated clinker grains, which contain tricalcium silicate, dicalcium silicate and ferrite phase.