Debonding failure along a softening FRP-to-concrete interface between two adjacent cracks in concrete members
Debonding failure along a softening FRP-to-concrete interface between two adjacent cracks in concrete members
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DOI：
10.1016/j.engstruct.2006.04.017
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发表时间：
2007-02-01
影响因子：
5.5
通讯作者：
Teng, J. G.
中科院分区：
文献类型：
--
作者：
Chen, J. F.;Yuan, H.;Teng, J. G.
混凝土梁可以通过在受拉面上粘接纤维增强聚合物（FRP）板来加强，这种梁的常见破坏模式包括在主要弯曲裂缝处开始的FRP板的剥离，这被广泛地称为中间裂缝（IQ剥离）。为了了解IC和其他脱粘失效，使用简单的拉脱试验广泛研究了FRP与混凝土之间的粘结行为，其中板与混凝土棱柱粘结并受到张力。然而，梁中frp -混凝土界面的行为可能与拉脱试验中捕获的情况有很大不同，因为在梁中，沿frp -混凝土界面的剥离是否发生在主要弯曲裂缝处，取决于该裂缝以及剥离扩展路径上相邻裂缝的条件。因此，本文研究FRP板两端受拉的FRP-混凝土粘结节点的脱粘过程，该过程与受弯钢筋混凝土构件的TC脱粘过程非常接近。同样的问题也是作者之前研究的主题，其中采用双线性局部粘结滑移模型来研究frp与混凝土的界面。然而，该解决方案相当复杂，难以在实践中应用。本研究的目的是通过采用简单的线性软化局部粘滑定律来产生一个简化的解决方案。将此简化解析解的结果与先前解的结果进行了比较，结果表明，在预测荷载-位移响应和极限荷载方面，精度几乎没有损失。新解决方案最重要的成果是一个简单的结合接头极限载荷表达式，为直接实际应用提供了潜力。虽然本文的重点是frp -混凝土连接，但解决方案和方法适用于其他材料之间的类似连接，如frp -钢或钢-混凝土粘合连接。(c) 2006 Elsevier Ltd.版权所有。
A concrete beam can be strengthened by bonding a fibre reinforced polymer (FRP) plate to the tension face, and a common failure mode for such beams involves the debonding of the FRP plate that initiates at a major flexural crack, which is widely referred to as intermediate crack (IQ debonding. To understand IC and other debonding failures, the bond behaviour between FRP and concrete has been studied extensively using simple pull-off tests, in which a plate is bonded to a concrete prism and is subject to tension. However, the behaviour of the FRP-to-concrete interface in a beam can be significantly different from that captured in a pull-off test as, in a beam, whether debonding along the FRP-to-concrete interface occurs at a major flexural crack or not depends on the conditions at this crack as well as at the adjacent crack on the path of the debonding propagation. This paper is therefore concerned with the debonding process of an FRP-to-concrete bonded joint where the FRP plate is subject to tension at both ends, which closely approximates the TC debonding process in a flexurally strengthened RC member. The same problem has been the topic of a previous study by the authors, where a bilinear local bond-slip model was employed for the FRP-to-concrete interface. However, that solution is rather complex and difficult to apply in practice. The aim of this study is to produce a simplified solution by employing the simple linearly softening local bond-slip law for the interface. Results from this simplified analytical solution are compared with those from the previous solution, showing little loss of accuracy in predicting the load-displacement response and the ultimate load. The most significant outcome of the new solution is a simple expression for the ultimate load of the bonded joint which offers the potential for direct practical application. While the emphasis of the paper is on FRP-to-concrete joints, the solution and methodology are applicable to similar joints between other materials such as FRP-to-steel or steel-to-concrete bonded joints. (c) 2006 Elsevier Ltd. All rights reserved.