热水养护对超高性能混凝土力学性能及水化过程的影响

Influence of Hot Water Curing on Mechanical Properties and Hydration Process of Ultra-high Performance Concrete

养护机制是影响混凝土质量的关键因素之一。采用热水养护机制,与标养28天的数据进行对比,从抗压强度、超声波速及微观特征等方面,初步探究养护温度及养护龄期对含粗骨料超高性能混凝土力学性能的影响规律及作用机理。结果表明:相较于标准养护,热水养护中较高温度(≥70℃)的所有组别1天后强度已大幅超越标养28天的强度,但后期会出现强度倒缩的现象。较低温度(<70℃)的部分组别可以通过延长养护龄期以达到强度要求。通过微观测试手段探究并验证热水养护温度对物相组成与孔结构的影响,为实际工程应用提供参考与帮助。

The curing mechanism is one of the key factors affecting the quality of concrete,Hot-water curing mechanism is adopted and compared with the data of standard curing for 28 days to explore the influence law and mechanism of curing temperature and curing age from the perspectives of compressive strength,ultrasonic pulse velocity and microcosmic characteristics.The results show that compared with standard curing,the strength of groups under hot water curing with a high temperature(≥70℃)after 1d has greatly exceeded the strength of the group under standard curing after 28 d.But in the later stage,there will be the phenomenon of strength shrinkage.Some groups under hot water curing with a low temperature(<70℃)can meet the strength requirement by extending the curing ages.By microscopic test means,the influence of hot water curing temperature on the composition and pore structure is explored and validated,which can provide a reference for practical engineering application.