高地温地下工程支护混凝土研究现状及进展

在系统分析高温对混凝土水化硬化的影响机理以及高温对混凝土结构带来的温度应力、强度和耐久性问题的基础上,针对高地温地下支护混凝土的研究和应用,总结了高温对围岩与喷射混凝土黏结强度、力学性能的作用机制,随后分别对矿物掺合料、轻质骨料、纤维等外掺料在提高混凝土的隔热性以及增强、阻裂等方面进行了综述,结果表明:矿物掺合料可降低...

Research Status and Development of Supporting Concrete for High Geothermal Underground Project

The effect of high temperature on hydration and hardening of concrete, as well as the temperature stress, strength and durability of concrete support structure are comprehensively analyzed. Taking account of the research and application of supporting concrete in high geo-temperature environment, the effect mechanism on the bonding strength and mechanical properties of rock-shotcrete at high geo-temperature are summarized. Then, the effects of mineral admixtures, fibers, lightweight aggregates and other admixtures on improving the thermal insulation, strengthen and crack resistance are reviewed. The results show that the mineral admixtures could improve the strength and durability of concrete in the later period, as well as increase the temperature threshold of negative temperature effect on concrete performance. The lightweight porous insulation materials introduced into concrete could achieve the thermal insulation effect. But nevertheless, this often leads to the reduction of mechanical performance. Based on the good understanding and grasp of the mechanism of high geo-temperature on the performance of composite supporting material, the light porous materials, mineral admixtures, fiber materials are added to concrete, and give full play to the synergistic effect of each component to achieve the balanced development of thermal insulation and supporting strength. At the same time, the implementation methods of simulating high geo-temperature environment in laboratory are introduced. Finally, the problems relating to further research are discussed and the potential application material is prospected.