Seismic rehabilitation of reinforced concrete beam-column joints by bonding with concrete covers and wrapping with FRP composites
Seismic rehabilitation of reinforced concrete beam-column joints by bonding with concrete covers and wrapping with FRP composites
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DOI：
10.1617/s11527-014-0511-4
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发表时间：
2016-01-01
影响因子：
3.8
通讯作者：
Tran, Tung M.
中科院分区：
文献类型：
--
作者：
Hadi, Muhammad N. S.;Tran, Tung M.
本研究评估了一种新的钢筋混凝土外部梁柱连接抗震加固方法的有效性，并为加固后的连接建立了节点抗剪强度模型。对4个无横向钢筋混凝土外连接进行浇筑和反循环荷载试验。第一个节点作为对照试件进行试验，其余三个节点在节点区柱周围粘贴混凝土盖板，使其由方形截面修改为圆形截面，然后用不同比例的碳纤维布包裹加固。基于平均平面应力概念建立了节点抗剪强度模型，并收集了32个常规FRP加固节点和3个新方法加固节点的数据，对节点抗剪强度进行了评估。试验结果表明，不同的CFRP包绕率导致连接破坏模式不同；尽管破坏模式有所不同，但加固节点的抗剪能力和抗震性能均有显著提高。新的加固方法可以消除现有方法的两个主要缺点（FRP从混凝土表面脱胶和/或胀形以及低约束效应）。试验和分析结果表明，新加固方法提高了FRP与混凝土共同抗联合剪力的能力。该模型能较准确地预测frp加固节点的抗剪强度。由于其优良的性能，所提出的强化方法和模型有望得到实际应用。
This study evaluates the effectiveness of a new method for seismic strengthening of exterior RC beam-column connections and develops a joint shear strength model for the strengthened connections. Four RC exterior connections without transverse reinforcement at the joints were cast and tested under reverse cyclic loading. The first connection was tested as the control specimen while the three remaining connections were glued with concrete covers around the columns at the joint area to modify them from square to circular sections and then they were wrapped with different ratios of CFRP for strengthening. The joint shear strength model was developed based on average plane stress concept and it was evaluated with a collected database containing 32 connections strengthened with the conventional FRP methods and three connections strengthened with the new method. Experimental results showed that the variation of the CFRP ratios wrapped around the specimens led to different failure modes of the examined connections; despite the differences in the failure modes, shear capacity and seismic performance of the strengthened connections improved significantly. The new strengthening method could eliminate two of the primary disadvantages (debonding and/or bulging of FRP from the concrete surface and a low confinement effect) of the existing method. The experimental and analytical results showed that the new strengthening method improved the ability of FRP and concrete working together to resist the joint shear forces. The proposed model predicted the joint shear strength of the FRP-strengthened connections accurately. Due to their superior performance, the proposed strengthening method and the proposed model are expected for practical application.