碳纤维复合材料-混凝土界面梁铰式疲劳试验与分析

发布时间：2019-01-07 07:40

【摘要】：外贴碳纤维增强复合材料(CFRP)-混凝土的界面抗疲劳性能是影响重复荷载作用下外贴CFRP加固混凝土梁加固效果的关键因素之一。基于梁铰式疲劳试验,对CFRP布-混凝土界面抗疲劳性能进行研究。试验结果表明:在黏结长度大于有效黏结长度时,重复荷载作用下CFRP布-混凝土界面的破坏过程可以分为初始剥离形成、剥离缓慢发展、剥离快速发展3个阶段,分别约占疲劳寿命的0~10%、10%~90%和90%~100%;在其他条件相同的情况下,提高混凝土强度或增加黏结长度可提高疲劳寿命,而随着CFRP布与混凝土宽度比的增大,疲劳寿命降低。基于试验结果,提出了考虑应力比(循环荷载作用下CFRP布的谷值应力与峰值应力之比)、混凝土强度、CFRP布与混凝土宽度比、黏结长度4个影响因素的CFRP布-混凝土界面的疲劳寿命曲线,并在传统疲劳寿命预测方法基础上,提出了考虑多因素的CFRP-混凝土界面疲劳寿命预测方法。
[Abstract]:The interfacial fatigue resistance of externally bonded carbon fiber reinforced composite (CFRP)-concrete is one of the key factors affecting the strengthening effect of concrete beams strengthened by externally bonded CFRP under repeated loads. Based on the beam hinge fatigue test, the fatigue resistance of CFRP-concrete interface is studied. The experimental results show that when the bonding length is larger than the effective bond length, the failure process of the interface between CFRP cloth and concrete under repeated load can be divided into three stages: initial peeling, slow development and rapid development. About 10% of the fatigue life and 90% of the fatigue life are about 10% and 100% of the fatigue life, respectively. Under the same conditions, the fatigue life can be increased by increasing the strength of concrete or by increasing the bonding length. However, the fatigue life decreases with the increase of the ratio of CFRP cloth to concrete width. Based on the test results, the ratio of stress ratio (the ratio of valley stress to peak stress of CFRP cloth under cyclic load), the strength of concrete and the ratio of width of CFRP cloth to concrete are proposed. The fatigue life curve of the interface between CFRP cloth and concrete with four factors affecting the bonding length is discussed. Based on the traditional fatigue life prediction method, a method for predicting the fatigue life of CFRP- concrete interface considering multiple factors is proposed.
【作者单位】：东南大学混凝土及预应力混凝土结构教育部重点实验室;郑州大学土木工程学院;
【基金】：国家973计划项目(2012CB026200)
【分类号】：TU377

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