外贴纤维与混凝土结合面的粘结滑移关系

Bond and slip relationship at the interface of bonded FRP and concrete

本文在外贴纤维复合材料(FRP)与混凝土结合面双剪试验中,采用电子散斑干涉技术(ESPI)对FRP-混凝土结合面的变形场进行了测试,重点研究了结合面的粘结滑移关系。试验结果表明,FRP-混凝土结合面的粘结滑移关系曲线的发展过程由非线性上升段和不稳定下降段两部分组成,峰值应力与混凝土强度有关,达到应力峰值时的滑移和极限滑移受混凝土强度和FRP的形式(板或布)等的影响不大。通过结合面滑移刚度衰减规律的分析,本文提出了FRP-混凝土结合面粘结滑移本构关系的基本模式,该模式基于FRP-混凝土结合面的初始(弹性)滑移刚度,力学概念明确。

In this paper, the electronic speckle pattern interferometry （ESPI） technique was used in a fiber reinforced polymer （FRP）-to-concrete double shear test to measure the full-flied deformation in the bonded area. Test results are used to study the bond-slip relationship at the interface. Test results show that the bond stress versus slip curve includes a nonlinear incremental portion and an unsteadily cloping portion. The strength of concrete is found to have a significant effect on the peak bond stress. Both the concrete strength and the form of FRP, either plate or sheet are found to have little influnce on the slip corresponding to the peak bond stress and the ultimate slip. Based on the trend analysis of degradation rule of bond stiffness at inferface, a basic model for bond and slip relationship at FRP-concrete interface is developed depending on the initial elastic bond stiffness.