摘要: |
为研究真实混凝土中氯盐的传输过程,采用X ray CT测试技术,原位重构了混凝土三维骨料分布与孔隙结构,建立了混凝土的三维细观数值模型;考虑界面过渡区(ITZ),并基于Fick第二定律,研究了氯离子在混凝土中的三维传输规律,同时通过电子探针技术验证了模型的准确性.研究表明:骨料表面的凸起及凹陷处对氯离子等值线的疏密、形状及扩散方向均有很大影响;不规则骨料增加了流线迂曲度,而ITZ的存在导致骨料周围形成快速传导路径,加快了氯离子的扩散速率. |
关键词: 混凝土 氯离子 细观结构 电子探针 |
DOI:103969/j.issn1007 9629202002007 |
分类号: |
基金项目:国家重点基础研究发展计划(973计划)项目(2015CB655103);国家自然科学基金资助项目(51320105013,51378012) |
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3D Mesoscopic Model for Chloride Transport in Concrete |
TIAN Ye, JI Haodong, TIAN Zushi, JIN Xianyu, YU Wei
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College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
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Abstract: |
In order to study the chloride transport process in real concrete, an electron probe technique was applied to establish a 3D mesoscopic numerical model of concrete by reconstructing the special aggregate distribution and pore structure. Taking the interfacial transition zone(ITZ) into consideration, the chloride transport in concrete was simulated based on Ficks second law. The model was verified through electron probe measurement. The research indicates that the outward and inward concave has impact on the density, outline and the chloride isolines of transfer direction. The irregular shape aggregate will enhance the tortuosity of transfer flux, while ITZ can provide a rapid transport path which will undoubtedly accelerate the chloride transfer. |
Key words: concrete chloride mesoscopic structure electron probe |