中文摘要：

为了准确计算钢筋腐蚀疲劳寿命,依据金属力学、电化学、断裂力学的基本原理,对混凝土中脱钝钢筋的腐蚀介质和疲劳荷载共同作用交互机理进行研究,建立脱钝后钢筋在疲劳荷载作用下同时考虑弹性变形、塑性变形和电化学作用的钢筋腐蚀速率模型,在此基础上构建了圆柱形钢筋腐蚀疲劳应力强度因子幅值的计算模型。定量分析了腐蚀疲劳裂纹扩展门槛值的理论计算模型以及钢筋腐蚀疲劳裂纹扩展模型,提出了腐蚀介质和疲劳荷载共同作用下钢筋寿命预测模式。利用已有文献中钢棒腐蚀疲劳试验结果对本文提出的模型以及寿命预测模式进行验证,结果表明,p H=2.5~12时钢棒腐蚀疲劳寿命计算值与试验值吻合较好,还揭示了疲劳荷载对钢筋腐蚀速度影响规律。

英文摘要：

Based on the basic principles of metal mechanics,electrochemistry,and fracture mechanics,studies of the interaction mechanism of corrosion medium and fatigue load of dispassivated reinforcement in the concrete structure have been carried out in order to accurately calculate the service life of the corroded reinforcement. A dispassivated reinforcement corrosion rate model considering the elastic deformation, plastic deformation and electrochemical action is established under the conditions of fatigue loads. On this basis,the calculation model for corrosion fatigue stress intensity factor amplitude of the cylindrical reinforcement is developed. The theoretical model for corrosion fatigue cracking propagation threshold and a reinforcement corrosion fatigue crack growth model are quantitatively analyzed. The reinforcement service life prediction model with corrosive medium and service loads is developed. The service life of the corroded reinforcement in the fatigue condition is calculated. Accoding to the steel bar corrosion fatigue test data in the references,the models and the method of the service life prediction are validated and the calculated results of steel bar corrosion fatigue life agree well with the test data when p H = 2. 5 ~12. The influence law of the fatigue loads on the steel corrosion rate is revealed through calculation and analysis of the service life.