| 摘要: |
| 采用不同的最大应力水平和不同的疲劳次数对C30混凝土进行拉伸疲劳试验，然后采用残余拉应变、基于超声波波速的疲劳损伤度和基于电化学阻抗谱的损伤电阻对拉伸疲劳后混凝土的疲劳损伤进行表征，研究混凝土氯离子扩散系数和疲劳损伤之间的关系.结果表明：残余拉应变越大，混凝土氯离子扩散系数也越大，残余拉应变25×10-6可以作为混凝土耐氯离子侵蚀性能的起劣点；混凝土氯离子扩散系数随着疲劳损伤度的增加而增大，两者之间呈指数函数关系；混凝土氯离子扩散系数随着损伤电阻的增大而减小，两者之间呈指数函数关系. |
| 关键词: 拉伸疲劳 氯离子扩散系数 疲劳损伤 残余拉应变 超声波波速 损伤电阻 |
| DOI：103969/j.issn1007 9629201603007 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51278167，51278168） |
|
| Effect of Tensile Fatigue on Diffusion of Chloride Ion in Concrete |
|
JIANG Linhua, ZHU Chenglong, XU Ning, LIU Hao, LI Bo, GAO Hailang
|
|
College of Mechanics and Materials, Hohai University, Nanjing 210098, China
|
| Abstract: |
| The tensile fatigue was enforced on C30 concrete with different maximum stress levels and different fatigue cycles. Residual tensile strain, fatigue damage degree based on ultrasonic velocity and damage resistance based on electrochemical impedance spectroscopy were used as the characterizations of fatigue damage to study the effect of tensile fatigue on the diffusion coefficient of chloride ion in concrete. It is shown that the diffusion coefficient of chloride ion in concrete increases with the increase of residual tensile strain. The residual tensile strain 25×10-6 could be used as a point where concrete starts degradation caused by chloride ion. The diffusion coefficient of chloride ion in concrete increases exponentially with the increase of fatigue damage degree. The diffusion coefficient of chloride ion in concrete decreases exponentially with the increase of damage resistance. |
| Key words: tensile fatigue diffusion coefficient of chloride ion fatigue damage residual tensile strain ultrasonic velocity damage resistance |
