Flexural behaviour of reinforced concrete beams strengthened with prestressed carbon composites
Flexural behaviour of reinforced concrete beams strengthened with prestressed carbon composites
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DOI：
10.1016/j.compstruct.2008.05.016
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发表时间：
2009-05-01
影响因子：
6.3
通讯作者：
Neale, Kenneth W.
中科院分区：
文献类型：
--
作者：
Yang, Dong-Suk;Park, Sun-Kyu;Neale, Kenneth W.
本研究共对13根frp加固钢筋混凝土梁进行了挠曲试验，并采用有限元方法进行了分析。各种变量包括FRP粘接或不粘接、锚固体系、预应力量和跨长。试验由1根对照梁、2根非预应力frp粘结梁、4根预应力frp无粘结梁、4根预应力frp无粘结梁和2根不同跨长的预应力frp无粘结梁组成。所有梁在挠度控制下进行三点和四点弯曲试验，记录荷载、挠度和破坏模式，直至破坏点。采用DIANA软件对试验梁进行了非线性有限元分析；该分析考虑了混凝土材料的非线性行为、钢筋和混凝土与碳纤维布板之间的界面粘结滑移模型。本研究的目的是研究CFRP板加固钢筋混凝土构件的抗弯性能，采用不同的FRP粘结和预应力方法。预应力cfrp梁的破坏模式不是剥离，而是FRP断裂。对于外粘预应力CFRP板加固的钢筋混凝土构件，复合层合板的剥离分两个阶段进行。粘结情况下CFRP板发生脱粘后，由于锚固体系的影响，粘结CFRP涂覆梁的性能转变为未粘结CFRP涂覆梁的性能。对cfrp加固梁的抗弯试验结果和分析预测结果进行了比较，结果表明，在脱粘荷载、屈服荷载和极限荷载方面，cfrp加固梁的抗弯试验结果非常一致。具有锚固体系的CFRP板加固梁的延性指数大于3时，认为其延性较高。(C) 2008 Elsevier Ltd版权所有。
In this study, a total of 13 FRP-strengthened reinforced concrete beams were tested in flexure and analyzed using the finite element method. The various variables included bonding or no bonding of the FRP, the anchorage system, the amount of prestressing, and the span length. The experiments consisted of one control beam, two non-prestressed FRP-bonded beams, four prestressed FRP-unbonded beams, four prestressed FRP-bonded beams, and two prestressed FRP-unbonded beams with different span lengths. All the beams were subjected to three-point and four-point bending tests under deflection control, with the loading, deflection and failure modes recorded to the point of failure. A nonlinear finite element analysis of the tested beams was also performed using the DIANA software; this analysis accounted for the nonlinear concrete material behaviour, the reinforcement, and an interfacial bond-slip model between the concrete and CFRP plates.The aim of this investigation was to study the flexural performance of reinforced concrete members strengthened using CFRP plates, employing different FRP bonding and prestressing methods. The failure mode of the prestressed CFRP-plated beams was not debonding, but FRP rupture. For the reinforced concrete members strengthened with externally bonded prestressed CFRP plates, debonding of the composite laminates occurred in two stages. After the debonding of the CFRP plates that occurred in the bonded cases, the behaviour of the bonded CFRP-plated beams changed to that of the unbonded CFRP-plated beams due to the effect of the anchorage system. The flexural test results and analytical predictions for the CFRP-strengthened beams were compared and showed very good agreement in terms of the debonding load, yield load, and ultimate load. The ductility of the beams strengthened with CFRP plates having the anchorage system was considered high if the ductility index was above 3. (C) 2008 Elsevier Ltd. All rights reserved.