掺MgO的RCC混凝土主要运用提高混凝土的防裂特性.通过外掺氧化镁碾压混凝土的特性试验研究,通过弹性模量与自生体积变形的试验,确定本文中碾压混凝土中恰当的MgO掺量为5.5%,并对马堵山大坝碾压混凝土的最大浇筑块的高温环境施工进行精确的温度场和应力场仿真计算,结果表明采用外掺氧化镁技术与埋设HDPE冷却水管相结合的措施对RCC高温施工的防裂是行之有效的温控防裂方法,为随后进行的马堵山碾压混凝土大坝高温环境的施工方案提供了重要的科学依据.%The addition of MgO to concrete proved to be an effective way to improving the crack-preventing properties of concrete . In this work, the optimal MgO content (5.5wt％) is obtained via investigating the addition of MgO on the modulus and autogenous growth of concrete carefully. Combining with temperature controlling units embedded inside the dam, concrete with optimized MgO content was applied in the construction of Madushan Dam under high temperatures. The temperature and stress field were monitored and simulated. The results showed that the addition of MgO combined with internal temperature controlling units could effectively reduce the maximum temperature, the temperature gap inside and outside as well as the maximum internal stress, which is well known for favoring the crack preventing in concrete curing under high temperatures.
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