FRP-混凝土界面剥离损伤的探测是界面力学分析的一个难点。基于三个标准试件探讨了红外检测方法对FRP-混凝土界面剥离探测的精度、可行性以及剥离判断的标准,并对常幅疲劳荷载下FRP加固钢筋混凝土(RC)梁界面的疲劳行为进行了跟踪记录,分析了界面的疲劳破坏过程。试验结果表明,FRP加固RC梁界面存在初始的未粘结区,在疲劳加载的初期界面剥离快速增加,随后在大部分疲劳寿命期内保持稳定,在最后数千次加载循环内界面损伤失稳发展导致整个加固构件的破坏。文中基于红外数据给出了每个阶段的疲劳加载次数和界面剥离损伤的面积。
The debonding detecting of FRP-concrete interface is a difficult problem in interface mechanics analysis.Infrared detection technology was used to record interfacial fatigue behaviors and analyze the interface fatigue damage processes.Based on three standard specimens,the probe accuracy,feasibility and interface debonding criterion of infrared detection measure were studied.Results show that initial debonding areas exist in the interface of RC beams strengthened with FRP.At an early stage during cyclic loading,the interfacial debonding expands rapidly then maintains stable in most fatigue life;the instability occurred during the last thousands cyclic loading results in a complete failure of strengthening RC beams.The fatigue loading number and the debonding area at every stages are presented in this paper based on infrared data.