摘要
通过室内干湿循环条件下混凝土中氯离子扩散试验,实测得到6种不同粗骨料体积分数的混凝土试件在不同时刻、不同深度处的氯离子浓度。经回归分析得到了不同粗骨料体积分数下混凝土的氯离子整体扩散系数,其值随粗骨料体积分数的增加而减小。同时,探讨了粗骨料的稀释、曲折和界面过渡区效应对混凝土中氯离子扩散的影响。在此基础上,同时考虑粗骨料体积分数Vf和界面过渡区厚度h的影响系数α(Vf,h),建立混凝土界面过渡区氯离子扩散系数模型,界面过渡区氯离子扩散系数随粗骨料体积分数的增大呈近乎线性地减小,随界面过渡区厚度的增大先显著减小而后逐渐趋于平稳。最后,将建立的界面过渡区氯离子扩散系数模型应用于混凝土中氯离子扩散的三维细观数模中。结果表明:细观数模计算结果与物理试验实测数据在变化趋势和数值大小上均能够吻合,可验证界面过渡区氯离子扩散系数模型的正确性与合理性。
The chloride ion content at different time and different depths of concrete specimens with six different coarse aggregates'volume fraction was measured in the chloride diffusion test under dry-wet cycling conditions.And the chloride diffusion coefficients of concrete with different coarse aggregates'volume fraction were obtained by regression analysis.Chloride diffusion coefficients decreased with the increase of coarse aggregate volume fraction.Meanwhile,the effects of dilution,tortuous and ITZ on chloride ion diffusion in concrete were discussed.On the basis of these,the chloride diffusion coefficients model of ITZ was established by introducing the influence coefficient a(Vr,h)considering the coarse aggregate volume fraction and the thickness of ITZ.The chloride diffusion coefficients of ITZ decreased linearly with the increase of coarse aggregate volume fraction,and decreased with the increase of the thickness of ITZ and then tended to be steady.Finally,the chloride diffusion coefficient model of ITZ was applied to three dimensional mesoscopic numerical simulation of chloride diffusion in concrete.The results show that microscopic numerical simulation results and physical test data are able to match in the trend of change and numerical size.And correctness and rationality of the chloride diffusion coefficient model of ITZ are verified.
作者
王元战
吕彦伟
龙俞辰
吴林键
WANG Yuanzhan;LYU Yanwei;LONG Yuchen;WU Linjian(National Key Laboratory of Water Conservancy Engineering Simulation and Security,Tianjin 300072,China;Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration,Tianjin University,Tianjin 300072,China;China Communications Fourth Design Institute of Navigation,Guangzhou 510230,China)
出处
《海洋工程》
CSCD
北大核心
2018年第2期73-82,共10页
The Ocean Engineering
基金
国家自然科学基金(51679166)
国家自然科学基金创新研究群体科学基金(51321065)
国家重点研发计划(2016YFC0802204)
交通运输部交通建设科技项目(2014328224040)
关键词
粗骨料
界面过渡区
氯离子扩散系数
细观数模
coarse aggregate
ITZ
chloride diffusion coefficient
mesoscopic numerical simulation
