| 摘要: |
| 通过室内NaCl溶液自然浸泡及快速冻融循环试验，研究了活性粉末混凝土在自然浸泡、冻融循环作用下的氯离子渗透情况，提出了冻融影响因子kd的计算方法.结果表明：自然浸泡条件下活性粉末混凝土中的氯离子扩散满足Fick第二定律，氯离子扩散系数随着时间的增长按指数形式衰减；冻融循环作用下活性粉末混凝土中的氯离子扩散系数随着冻融循环次数的增加先减后增.另外，分别建立了以冻融破坏为主要原因、以氯离子侵蚀破坏为主要原因以及在冻融循环与氯离子侵蚀耦合作用下的混凝土寿命预测模型，寿命预测结果表明活性粉末混凝土在冻融循环与氯离子侵蚀耦合作用下具有良好的耐久性. |
| 关键词: 活性粉末混凝土 冻融循环 氯离子侵蚀 氯离子扩散系数 寿命预测 |
| DOI：103969/j.issn1007 9629201605004 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51278039)；北京高等学校青年英才计划项目(YETP0563)；中央高校基本科研业务费专项资金资助项目(2014JBM086) |
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| Chloride Ion Distribution and Diffusion Coefficient of Reactive Powder Concrete under Freeze Thaw Cycling |
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WANG Yue1, AN Mingzhe1, YU Ziruo1, JIA Fangfang2
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1.School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China;2.Beijing Engineering Research Center of Architectural Functional Macromolecular Materials,Beijing Building Construction Research Institute Co., Ltd., Beijing 100039, China
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| Abstract: |
| The indoor tests of natural immersion in NaCl solution and fast freeze thaw cycling were carried out to study the chloride ion penetration to reactive powder concrete, and the calculation method of freeze thaw impact factor kd was put forward. The results show that chloride ion diffusion coefficient of specimens after natural immersion could be calculated based on Ficks second law, and it decreases as immersion time increases. However, the chloride ion diffusion coefficient decreases at first then increases as the cycle times increase. The life prediction models were established considering freeze thaw damage, chloride ion erosion, and combined effect of freeze thaw cycling and the chloride ion erosion. Life prediction results show that reactive powder concrete has a good durability under the combined action of freeze thaw cycling and chloride ion erosion. |
| Key words: reactive powder concrete freeze thaw cycle chloride ion erosion chloride ion diffusion coefficient life prediction |
