Research and application of cement-based rapid repair materials in low negative temperature environment

To study the performance of cement-based rapid repair materials under low negative temperature conditions, calcium aluminate was used as an activator to prepare rapid repair materials in cement-based materials. The effects of activator dosage on the mechanical and micro-performance of cement-based materials were tested. The results show that with increasing activator dosage, the slump first increases and then decreases. When the activator dosage is around 2%, the slump reaches its maximum. Subsequently, as the dosage increases, the slump gradually decreases. When the activator dosage is low, it has almost no effect on the strength of the cement-based material. When the activator dosage increases to 4%, the strength of the cement-based material reaches its peak, and further increases in dosage lead to a gradual stabilization of strength growth. Microscopic test results indicate that an appropriate amount of activator can improve the microstructure of low-temperature cement-based materials, reduce the porosity within the cement matrix, and enhance the density of low-temperature cement-based materials.