Strengthening of deficient RC jointswith diagonally placed external C-FRP ropes

IF 1.4 4区工程技术 Q3 ENGINEERING, CIVIL

Earthquakes and Structures Pub Date : 2021-01-01 DOI:10.12989/EAS.2021.20.1.123

C. Karayannis, Emmanouil Golias

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引用次数: 13

Abstract

Deficient beam-column joints of reinforced concrete (RC) structures designed to older practices and codes often lead to destructive local or global failures. A strengthening technique for these joints based on the use of the new and innovative Carbon-FRP (C-FRP) ropes is presented and investigated. The C-FRP ropes are diagonally placed in superficial notches on the two sides of the joint. Two full scale external substandard joint subassemblages with the same characteristics, one unstrengthened and one strengthened with diagonally applied C-FRP ropes, are constructed and tested in cyclic loading. Special attention has been given to the elaboration of the acquired test measurements. The extracted conclusions are based on the comparative study of the hysteretic responses of the specimens, the observed maximum load envelopes, the comparisons of the joint body shear deformations as measured using diagonally mounted LVTDs, the calculated nominal principal stresses developed in the joint regions, the assessed joint damage as expressed by the damage index by Park and Ang and finally the calculated values of the equivalent damping ratio. From these comparisons it is concluded that application of diagonally mounted C-FRP ropes on the two sides of the joint body of exterior connections is an efficient easy-to-apply technique for the strengthening of substandard RC joints.

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斜线外置C-FRP绳加固缺陷RC节点

按旧规范设计的钢筋混凝土(RC)结构的梁柱节点缺陷常常导致破坏性的局部或整体破坏。提出并研究了一种基于新型碳- frp (C-FRP)绳索的接缝加固技术。C-FRP绳对角放置在接头两侧的表面缺口中。构建了两个具有相同特性的全尺寸外标接头组件，一个未加固，一个斜向应用C-FRP绳加固，并进行了循环加载试验。特别注意了所获得的试验测量的详细说明。所得结论是基于对试件的滞回响应、观测到的最大荷载包络、对角线安装LVTDs测量的节理体剪切变形的比较、计算出的节理区域的名义主应力、Park和Ang用损伤指数表示的评估的节理损伤以及计算出的等效阻尼比值。通过比较，得出在外连接节点两侧斜装C-FRP绳是加固不合格钢筋混凝土节点的一种有效易行的方法。

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来源期刊

Earthquakes and Structures ENGINEERING, CIVIL-ENGINEERING, GEOLOGICAL

CiteScore

2.90

自引率

20.00%

发文量

审稿时长

>12 weeks

期刊介绍： The Earthquakes and Structures, An International Journal, focuses on the effects of earthquakes on civil engineering structures. The journal will serve as a powerful repository of technical information and will provide a highimpact publication platform for the global community of researchers in the traditional, as well as emerging, subdisciplines of the broader earthquake engineering field. Specifically, some of the major topics covered by the Journal include: .. characterization of strong ground motions, .. quantification of earthquake demand and structural capacity, .. design of earthquake resistant structures and foundations, .. experimental and computational methods, .. seismic regulations and building codes, .. seismic hazard assessment, .. seismic risk mitigation, .. site effects and soil-structure interaction, .. assessment, repair and strengthening of existing structures, including historic structures and monuments, and .. emerging technologies including passive control technologies, structural monitoring systems, and cyberinfrastructure tools for seismic data management, experimental applications, early warning and response