基于混凝土三维CT重构氯离子扩散过程数值模拟  

Numerical Simulation of Chloride Diffusion Process Based on Three-dimensional CT Reconstruction of Concrete

作　　者：陈宣东 刘光焰[1,2] 王晓峰[1,2] 黄达[1,2] CHEN Xuan-dong;LIU Guang-yan;WANG Xiao-feng;HUANG Da(Guangxi Key Laboratory of New Energy and Building Energy Saving,Guilin University of Technology,Guilin 541004,China;College of Civil and Architecture Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学广西建筑新能源与节能重点实验室,广西桂林541004 [2]桂林理工大学土木与建筑工程学院,广西桂林541004

出　　处：《水电能源科学》2020年第3期117-120,共4页Water Resources and Power

基　　金：国家自然科学基金项目(51468014);广西建筑新能源与节能重点实验室(桂科能17-J-21-7);广西建筑新能源与节能重点实验室基金(桂科能-J-21-30);桂林理工大学研究生创新项目(SS201604)。

摘　　要：近年来,氯盐导致钢筋混凝土结构耐久性失效问题,氯离子破坏钢筋表面的钝化膜,加速了钢筋的锈蚀,同时裂缝的存在促进了氯离子的扩散,从而形成了恶性循环。基于混凝土三维CT重构技术,建立了湿-热-氯盐-裂缝多场耦合的氯离子扩散数值模型,研究了裂缝宽度、深度、等效裂缝形式对混凝土内氯离子分布的影响。结果表明,裂缝宽度促进了氯离子的扩散,但裂缝中氯离子浓度不与裂缝宽度成正比,裂缝宽度对氯离子浓度分布影响随着裂缝宽度的增加在减弱。裂缝深度对钢筋表面氯离子浓度具有显著影响,在诸多因素中起控制作用,采用楔形裂缝形态模拟氯离子在混凝土中分布与实际情况较吻合。In recent years,the durability failure of reinforced concrete structures was caused by chlorine salts.Chloride ions destroy the passive film on the surface of steel bar,and accelerate the corrosion of steel bar.Meanwhile,the existence of cracks promotes the diffusion of chloride ions,thus forming a vicious circle.Based on the three-dimensional CT reconstruction technology of concrete,a numerical model of chloride diffusion with multi-field coupling of wet-heat-chlorine salt-cracks is proposed.The influence of crack width,depth and equivalent crack form on the distribution of internal chloride ion in concrete is studied.The results show that the crack width promotes the diffusion of chloride ions,but the chloride concentration in cracks is not proportional to the width of cracks.The effect of crack width on chloride concentration distribution decreases with the increase of crack width.The crack depth has a significant influence on the concentration of chloride ion on the surface of the steel bar,and it plays a controlling role in many factors.The distribution of chloride ion in concrete is in good agreement with the actual situation of the cuneiform fracture.

关 键 词：氯盐 数值模拟 裂缝 扩散系数 三维CT重建 

分 类 号：TU528[建筑科学—建筑技术科学]