管片混凝土变扩散系数氯离子侵蚀模型  

Model of Chloride Ion Erosion in Segment Concrete Considering Variable Diffusion Coefficients

作　　者：李智[1,2] 彭立敏[1] 施成华[1] 

机构地区：[1]中南大学土木工程学院,长沙410004 [2]广州地铁设计研究院有限公司,广州510010

出　　处：《现代隧道技术》2014年第1期105-109,152,共6页Modern Tunnelling Technology

基　　金：国家重点基础研究发展计划资助项目(973:2011CB013802);国家自然科学基金资助项目(51278494);湖南省高校创新平台开放基金项目(10K75)

摘　　要：文章通过对管片混凝土氯离子侵蚀机理的分析,在Fick第二扩散定律基础上,推导出了综合考虑时间、扩散深度的变扩散系数氯离子侵蚀模型;通过对管片抗侵蚀性能试验数据的分析,验证了该侵蚀模型的有效性和可靠性,并与传统的恒定扩散系数的Fick第二扩散定律模型进行了对比。分析结果表明:该模型不仅能反映结构实际受氯盐侵蚀的发展趋势和混凝土不同深度处的氯离子浓度,而且能预测不同时期、不同深度处的氯离子含量,进而可预测钢筋开始锈蚀的时间。By analyzing the mechanism of chloride ion erosion in concrete segments, andbased on the Fick second diffusion law, the chloride ion erosion model with variable diffusion coefficients was set up , in which the time, and diffusion depth were taken into consideration comprehensively. The effectiveness and reliability of this model was verified by an analysis of experimental data concerning the anti-erosion performance of tunnel segments. Compared to the conventional Fick second diffusion law model considering constant diffusion coefficients, this model can not only reflect the development trend of chloride ion erosion of the structure itself and the chloride ion concentration in concretes at various depths, but also predict the chloride ion content in different phases or at various depths. Furthermore, it can predict when corrosion will occur in reinforcements.

关 键 词：管片混凝土 变扩散系数 FICK第二定律 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]