Abstract Lack of joint confinement for the majority of pre-1970 reinforced concrete (RC) frame construction has resulted in weakening the link between the column and the beam and collapse of the whole structure. The main focus of this research study is based on four interrelated tasks: (i) design and development of innovative repair and retrofit techniques for reinforced concrete (RC) beam-column joints using advanced FRP composite laminates and pre-cured composite connectors; (ii) experimental evaluation of the different techniques using full-scale testing; (iii) comparison in behavior between as-built and different retrofit specimens; and (iv) conclusions and recommendations for future research. Experimental results confirmed the superiority and success of the proposed strengthening protocols, not only in restoring the original strength capacity, but also in enhancing the overall seismic performance of the deficient joints evaluated in this study including strength and ductility. For example, the use of carbon/epoxy wet layup composite laminates resulted in an appreciable increase of both strength and ductility up to 1.34 and 3.04 times, as compared with as-built specimen, respectively. Also, the proposed technique for enhancing shear strength and rebar bond slippage of the joints using high-strength carbon/epoxy FRP composite laminates and a hybrid composite connectors (HCC) achieved significant results. The novel proposed technique improved the shear strength of the joint 2.5 times the control deficient specimen. The use of the hybrid composite connector (HCC) succeeded in relocating the hinging mechanism to form in the beam span away from the joint region. The ductility of the retrofitted specimen was 2.18 times the control (as-built) specimen. It is anticipated that the results of this pioneering study will provide alternative innovative reinforcing and strengthening methodologies to enhance the construction and repair methods for reinforced concrete moment frame structures. These innovative techniques contribute to higher reliability and safety, as well as lower construction and repair costs of RC moment frame structures. It is also anticipated that the proposed strengthening protocol can also be applied to cover similar details such as base-column, pile-cap as well as T- and knee bridge joints.

中文翻译：

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FRP复合材料加固室内RC梁柱节点抗震性能试验评价

摘要 1970 年以前的钢筋混凝土 (RC) 框架结构中，大多数缺乏节点约束，导致柱与梁之间的联系弱化，导致整个结构倒塌。本研究的主要重点基于四个相互关联的任务：(i) 使用先进的 FRP 复合材料层压板和预固化复合材料连接件，设计和开发钢筋混凝土 (RC) 梁柱节点的创新修复和改造技术；(ii) 使用全面测试对不同技术进行实验评估；(iii) 竣工和不同改造样本之间的行为比较；(iv) 对未来研究的结论和建议。实验结果证实了所提出的强化方案的优越性和成功性，不仅在恢复原始力量能力方面，而且还可以提高本研究中评估的缺陷节点的整体抗震性能，包括强度和延展性。例如，与竣工试样相比，使用碳/环氧树脂湿法叠层复合层压板使强度和延展性分别提高了 1.34 倍和 3.04 倍。此外，所提出的使用高强度碳/环氧树脂 FRP 复合层压板和混合复合连接器 (HCC) 提高接头剪切强度和钢筋粘结滑移的技术取得了显着的成果。新提出的技术将接头的剪切强度提高了 2.5 倍于对照缺陷试样。混合复合连接件 (HCC) 的使用成功地将铰接机构重新定位，以在梁跨距中形成远离接头区域。改造后的试样的延展性是对照（竣工）试样的 2.18 倍。预计这项开创性研究的结果将提供替代的创新加固和加固方法，以增强钢筋混凝土框架结构的施工和修复方法。这些创新技术有助于提高 RC 力矩框架结构的可靠性和安全性，并降低其建造和维修成本。预计拟议的加固协议也可用于涵盖类似的细节，如基柱、桩帽以及 T 型和膝桥关节。预计这项开创性研究的结果将提供替代的创新加固和加固方法，以增强钢筋混凝土框架结构的施工和修复方法。这些创新技术有助于提高 RC 力矩框架结构的可靠性和安全性，并降低其建造和维修成本。预计拟议的加固协议也可用于涵盖类似的细节，如基柱、桩帽以及 T 型和膝桥关节。预计这项开创性研究的结果将提供替代的创新加固和加固方法，以增强钢筋混凝土框架结构的施工和修复方法。这些创新技术有助于提高 RC 力矩框架结构的可靠性和安全性，并降低其建造和维修成本。预计所提出的加固协议也可用于涵盖类似的细节，如基柱、桩帽以及 T 型和膝桥关节。