为了探讨模拟环境中混凝土表面与环境间水分传输边界条件,通过模拟试验分析了混凝土的干燥失水变化规律,研究了水灰比和温度等对混凝土水分扩散表面因子变化的影响;此外,还利用数值模拟探讨了人工模拟环境中风速对混凝土水分扩散表面因子和混凝土内湿度分布状态的影响。结果表明:所提出的人工模拟环境中混凝土水分传输表面因子模型可描述温度和风速对混凝土表面因子的影响规律;混凝土表面孔隙面积率可用以表征水灰比对其表面水分传输的影响,且两者间呈指数函数关系;若人工模拟环境中风速和干燥时间超过某定值(约为3 m·s-1),则可将环境湿度视为混凝土与环境间的界面湿度,可为确定人工模拟试验环境风速参数提供理论依据。
Abstract
In order to investigate the moisture transmission boundary condition between concrete surface and artificial simulation environment, with the simulation test, the law of drying process in concrete under artificial simulation environment was analyzed. The influences of water to cement ratio and temperature on the surface factor were investigated. Moreover, the impact of wind speed on the surface factor and the moisture distribution in concrete was investigated by means of numerical simulation. The results show that the influences of temperature and wind speed on the concrete surface factor can be described by the concrete moisture transmission surface factor model under artificial simulation environment. Meanwhile, the concrete surface pore area ratio is recommended as a parameter to characterize the effect of water to cement ratio on the concrete moisture transmission surface factor, and correlation of them exactly follows exponential function. When wind speed and drying time are more than a certain fixed value such as 3 m·s-1, the humidity of artificial simulation environment can be regarded as the interface humidity between concrete and environment. From above research, the theoretical basis for the wind speed value in artificial simulation environment is determined.
关键词
桥梁工程 /
水分传输 /
试验研究 /
边界条件 /
表面因子
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Key words
bridge engineering /
moisture transmission /
experimental research /
boundary condition /
surface factor
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中图分类号：
U445.75
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脚注
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基金
国家自然科学基金项目(51278496,51408614,51378312,U1434204);中国铁路总公司科技研究开发计划项目(2014G010-A)
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