| 摘要: |
| 对3种强度等级的混凝土进行了密封养护下内部相对湿度和自由变形的试验测定，获得了从混凝土浇注开始到77d龄期混凝土内部湿度和自由变形的发展数据，同时对混凝土因水泥水化引发的自干燥和自收缩问题进行了模拟.结果表明：混凝土内部相对湿度和收缩具有较好的同步性；混凝土内部湿度变化可以看作是其自收缩变化的驱动力；水灰比越小，自干燥引起的混凝土内部相对湿度下降幅度越大，密封条件下混凝土的收缩也越大；以水泥水化度和混凝土内部湿度为内因的自干燥与自收缩模型较好地模拟了密封条件下混凝土内部湿度变化与相应的自收缩发展.试验结果与模型预测值吻合良好，模型可用于不同养护环境下混凝土自干燥与自收缩的分析预测. |
| 关键词: 混凝土 密封养护 相对湿度 自干燥 自收缩 |
| DOI：10.3969/j.issn.1007 9629.2013.02.004 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（50978143,51178248）；国家重点基础研究发展计划（973计划）项目（2009CB623200）；高等学校博士学科点专项科研基金资助项目（20100002110016）；清华大学黄廷芳信和教育基金资助项目 |
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| Tests and Simulations of Interior Humidity and Shrinkage ofConcrete under Sealed Condition |
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GAO Yuan1, ZHANG Jun1, SUN Wei2
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1.Department of Civil Engineering, Tsinghua University, Beijing 100084, China;2.School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
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| Abstract: |
| The deformation and interior humidity of the concrete specimen under sealed condition were continuously measured for at least 77 d and the simulation of concrete self desiccation and autogenous shrinkage caused by cement hydration was done. The experimental results show that the development of shrinkage and the interior humidity are of high synchronicity. The interior humidity may serve as the driving force parameter for concrete deformation. The lower the water to cement ratio is, the larger the variation of relative humidity caused by self desiccation and concrete shrinkage are. The calculation models of concrete self desiccation and autogenous shrinkage based on the cement hydration degree and interior humidity can well simulate the development of concrete interior humidity and autogenous shrinkage. The results of the model prediction are in agreement with the test data and the calculation models can be used for the prediction of concrete self desiccation and autogenous shrinkage under different curing conditions. |
| Key words: concrete sealed curing relative humidity self desiccation autogenous shrinkage |
