疲劳荷载下CFRP布加固损伤钢筋混凝土梁粘结性能试验分析

在加固工程中,CFRP布-混凝土界面的有效粘结是决定加固效果的关键因素。针对四根已产生疲劳损伤的足尺钢筋混凝土梁进行CFRP布加固,考虑原钢筋混凝土梁损伤程度和疲劳幅值影响,对CFRP布加固损伤钢筋混凝土梁界面的粘结性能进行疲劳试验研究,探讨CFRP布-混凝土界面在疲劳荷载作用下的粘结应力分布以及加固后试验梁的疲劳粘结性能。结果表明:试验梁初始损伤程度和疲劳幅值越大,CFRP布-混凝土界面的粘结性能越差,疲劳寿命越小;当疲劳幅值超过0. 6时,加固梁的疲劳寿命急剧下降,发生脆性疲劳粘结破坏。

Experimental analysis on bond performance of damaged concrete beams reinforced with CFRP sheets under fatigue load

In the reinforcement project,the bond performance of the interface between CFRP sheets and concrete is a key factor that determines the effectiveness of the reinforcement.Four full-scale reinforced concrete beams with fatigue damage were reinforced with CFRP sheets.Considering the impacts of damage degree of the original reinforced concrete beams and fatigue amplitude,the fatigue test was carried out on the bonding performance of damaged reinforced concrete beams reinforced with CFRP sheets.The bond stress distribution of interface between CFRP sheets and concrete under fatigue load and the fatigue bond performance of reinforced test beams were discussed.The results show that the greater the initial damage degree and fatigue amplitude of the test beam are,the worse the bonding performance of interface between CFRP sheets and concrete is and the smaller the fatigue life is;when the fatigue amplitude exceeds 0.6,the fatigue life of the reinforced beam decreases sharply and brittle fatigue bond failure occurs.