An experimental and numerical program is carried out in this research to investigate the influence of CFRP sheets on the cyclic behavior of unconfined connections made with recycled concrete. Cement is partially replaced by silica fume, iron filling and pulverised fuel ash using two different percentages: 15% and 20%. Each specimen is partially loaded at the first stage and then specimens are repaired using CFRP sheets. The repaired specimens are then laterally loaded until failure. In addition, a finite element model is built in ABAQUS and verified using the experimental results. The experimental results have shown that the repaired specimens have regained almost double the capacity of the un-repaired specimens and hence the adopted repair configuration is recommended for retrofitting seismically vulnerable RC connections. Increasing cement replacement percentage by silica fume, fuel ash or iron filling from 15% to 20% has reduced joint carrying capacity and weakened the joint. It is recommended using 15% pulverised fuel ash or silica fume as cement partial replacement to enhance the strength and ultimate drift of beam-column joints under cyclic loading. Iron filling concrete is also recommended but the enhancement is relatively less than that found with pulverised fuel ash concrete and silica fume concrete.

中文翻译：

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使用CFRP板对由再生混凝土制成的严重损坏的RC连接进行抗震改造

在这项研究中，进行了实验和数值程序，以研究CFRP板对再生混凝土制成的无边连接的循环行为的影响。水泥被二氧化硅粉，铁填充物和粉状燃料灰分部分替代，使用两种不同的百分比：15％和20％。每个样品在第一阶段都会部分加载，然后使用CFRP板修复样品。然后将修复后的样品横向加载，直到失效。此外，在ABAQUS中建立了有限元模型，并使用实验结果对其进行了验证。实验结果表明，修复后的标本已恢复了未修复标本的几乎两倍的容量，因此，建议采用采用的修复配置来翻修地震脆弱的RC连接。硅粉，燃料灰分或铁填充物将水泥替代百分比从15％增加到20％，降低了接头的承载能力并削弱了接头。建议使用15％的粉煤灰或硅粉作为水泥的部分替代品，以提高循环荷载下梁柱节点的强度和最终位移。还推荐使用铁填充混凝土，但其增强程度相对于粉煤灰和硅粉混凝土而言要小得多。