Abstract
The characteristics of cinker in the C3S-C2S-C11A7 ·CaF2-C4AF system vary depending on the cooling rate and change the early hydraulic properties of the cement. The size of alite becomes small with cooling rate and the fine crystals of alite which precipitated at cooling process coexist with the crystals of alite which precipitated at burning process in case of rapid cooling. The above changes in fine textures have a close relationship to the content of SiO2 in the solid solution of C11 A7·CaF2. The amount of SiO2 and other impurities in C11A7·CaF2 give a considerable influence on the early hydraulic activity of the phase; with the decrease in impurities, that is, with the decrease in cooling rate, the activity becomes high.
