【作者】 刘燕；

【导师】 易成；

【作者基本信息】 中国矿业大学（北京） ， 结构工程， 2011， 博士

【摘要】 混凝土结构是应用非常广泛的的一种结构形式,其耐久性研究是当前重要的研究课题。本文基于当前现状的分析总结,通过劈拉试验及数值模拟,建立微裂纹损伤参量,分析了混凝土微裂纹缺陷对氯离子渗透性能的影响；并基于此,引入模糊理论,建立了氯离子侵蚀环境下混凝土结构模糊时变可靠度分析模型。本文通过对混凝土试件四个方向上的旋转劈拉试验,构建相对均匀的损伤场,利用数字散斑技术对试件表面的位移场进行全方位分析,同时对混凝土劈拉过程进行ANSYS全程数值模拟,通过试验和模拟结果的相互比较验证,建立了微裂纹损伤参量(基于MCOD值的损伤面积ω和基于加权弹模衰减的损伤变量DE)；同时,利用饱盐混凝土电导率法(NEL法),对劈拉损伤前后的混凝土试件氯离子渗透性能进行分析,探讨微裂纹损伤参量和氯离子扩散系数变化率之间的关系；通过引入材料劣化效应系数K值,探讨微裂纹损伤对混凝土结构氯离子侵蚀环境下预测寿命的影响,引入考虑微裂纹对氯离子渗透性能影响的衰减函数并借助于模糊理论,建立氯离子侵蚀环境下,考虑微裂纹现状的混凝土结构模糊时变可靠度分析模型,对混凝土结构氯离子侵蚀耐久性能的评估方法进行探讨。更多还原

【Abstract】 Reinforced concrete structure is one kind of structural style which is used extremely widespread, and the durability study is a significant project in the research of RC structure. Based on the predecessors’research, the effect of structural micro-crack defect to the Cl- permeation of concrete are analyzed through the experimental analysis and numerical simulation. On the previous foundations, fuzzy timevariant reliability model for the concrete structure Cl- permeation durability is established by the application of fuzzy theory and membership function.The concrete specimens are split from the four different dimensions in the splitting experiment in order to build the even damage fields. The displacements of the concrete specimens’surface are analyzed through DSCM(Digital Speckle Correlation Method). Further more, ANSYS numerical simulation for the concrete splitting process is established which can verify the experimental results each other. Therefore damage parameters are determined that are damage area based on the MCOD(Micro-Crack Opening Displacement) and damage variable based on the weighting-damping elastic modulus. At the same time, Cl- permeation of concrete specimens before and after the splitting test are all studied by NEL method, and diffusion coefficients of Cl- are recorded in detail. Further relationships between the damage parameters and diffusion coefficients of Cl- are discussed. The effects of structural micro-crack defect to predection life of concrete structure in the Cl- environment are discussed through the material degradation effective coefficient K. Finally fuzzy timevariant reliability model for the concrete structure Cl- permeation durability is established by the application of fuzzy theory and attenuation function, which is effective through the example confirmation. Therefore the new durability evaluation method for the in-service concrete structure in the Cl- environment is discussed.更多还原