钢筋与混凝土界面的腐蚀疲劳

腐蚀疲劳是钢筋混凝土结构破坏的主要因素之一。基于剪切筒模型及文中选用的实验加载方式 ,引入界面摩擦系数衰减表达式 ,同时考虑力学因素———应力比R和加载频率 f的影响 ,研究了钢筋与混凝土界面在拉 -拉循环荷载作用下腐蚀疲劳裂纹扩展情况。通过对Paris公式的修正 ,借助能量耗散率给出腐蚀疲劳数学模型 ,得到了界面腐蚀疲劳脱粘速率 ,脱粘长度与循环荷载作用次数的关系。最后与无腐蚀情况的结果进行比较 ,分析了影响界面腐蚀疲劳 (CF)裂纹扩展速率的因素 ,如应力比 ,加载频率。

Corrosion Fatigue at the Interface of Reinforcing Bar and Concrete

Corrosion fatigue is one of the main factors damaging the structures of reinforced concrete. Based on the shear lag model and the experimental loading way, expression of the degradation of interfacial friction coefficient is introduced. At the same time, the impact of the ratio R of mechanical factors and stress and the loading frequency f is taken into consideration. Under this condition, the crack growth due to interfacial corrosion fatigue in reinforced concrete under tension tension cyclic loading is investigated. With the aid of dissipation rate of energy and modifying the Paris formula, the mathematical model of corrosion fatigue is given, and the relationships between interfacial debonding rate of CF,debonding length and the number of cyclic loading are obtained. Compared with the results without corrosion, the factors influencing the crack growth rate of CF are analyzed, such as stress ratio, loading frequency.