Abstract: The influence of the curing temperature (150 °C, 200 °C, 250 °C, and 300 °C) and curing time (4 h, 8 h, and 12 h) on the mechanical properties and shrinkage development of reactive powder concrete (RPC) was studied, and a curing regime for improving its mechanical properties is proposed. Test results show that the compressive and flexural strengths of specimens increase at curing temperatures of 200 °C to 250 °C, but decrease at curing temperature of 300 °C. Meanwhile, shrinkage measurement results indicate that the ultimate shrinkage of high-temperature cured RPC at 50% relative humidity (RH) is lower than in the control group. Scanning electron microscope results reveal that high-temperature curing improves the microscopic pore structure of RPC and makes the interfacial transition zone denser. Furthermore, the dry-heat curing regime can accelerate the cement hydration process, and tobermorite or xonotlite was found to be one of the major crystalline hydrates at high temperature.

干热养护对活性粉末混凝土力学及收缩影响研究

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