2023 Volume 77 Issue 1 Pages 145-152
In order to improve strength development in low-temperature environments, high-early strength cement with high C3A content was prepared in an electric furnace and a test rotary kiln, and early age strength and hydration reactivity at 5℃ or 10℃ were compared with those of High early strength cement. The early age strength in low temperature was evaluated using mortar and concrete, white the hydration of the cement was investigated using Quantitative X-Ray Diffraction, and Isothermal calorimetry. The size of C3A crystals was evaluated by light microscope. The results showed that higher IM led to larger crystal growth and the higher reactivity of C3A. In addition, it was found that the reactivity of C3S was also accelerated along with the improvement of C3A reactivity, resulting in the improvement of early age strength at low temperatures. Mortar strength of the high-early strength cement with high C3A content was higher than that of high early-strength cement, in which were increased the blaine specific surface area and added potassium sulfate and calcium nitrite. Moreover, the strength of the concrete of the high-early strength cement with high C3A content was also higher than that of the high early-strength cement at 5℃. These results indicate that high-early strength cement with high C3A content has excellent early age strength development in low-temperature environments.
