Application of ultra-high performance fiber reinforced concrete for retrofitting the damaged exterior reinforced concrete beam-column joints

IF 1.4 4区工程技术 Q3 ENGINEERING, CIVIL

Earthquakes and Structures Pub Date : 2020-11-01 DOI:10.12989/EAS.2020.19.5.361

Mohammed Al-Osta, Muhammad Irfan Khan, Ashraf A. Bahraq, Shi-Yu Xu

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引用次数: 5

Abstract

In the present research work, the effectiveness and the efficiency of a retrofitting approach using a layer of ultra-high performance fiber reinforced concrete (UHPFRC) jacket for damaged substandard exterior beam-column joints (BCJs) is experimentally investigated. The main objective of this study is to rehabilitate the already damaged BCJs to meet the serviceability requirements without compromising safety. According to the proposed strengthening technique, a chipped surface, lightly brushed with a dry condition was selected for making a successful bond between normal concrete substrate surface (NCSS) and UHPFRC. Then a fresh UHPFRC jacket with a thickness of 30 mm was cast around the damaged specimens. The entire test matrix was comprised of three 1/3 scale damaged exterior BCJs with a different column axial load (CAL). These specimens were repaired with UHPFRC and retested under monotonic loading. Based on the experimental results, repaired specimens showed an excellent performance in terms of their load-displacement response, maximum strength, displacement ductility, initial stiffness, secant stiffness and energy dissipation capacity when compared with the corresponding values registered when these specimens were tested in their virgin state. This rehabilitative intervention not only restored the strength, stiffness, ductility and energy dissipation capacity of severely damaged specimens but also improved their performance.

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超高性能纤维混凝土在钢筋混凝土外梁柱节点损伤修补中的应用

在目前的研究工作中，通过实验研究了使用一层超高性能纤维混凝土（UHPFRC）护套对损坏的不合格外梁柱节点（BCJs）进行改造的有效性和效率。本研究的主要目的是在不影响安全的情况下，修复已经损坏的BCJ，以满足可用性要求。根据所提出的加固技术，选择了一种在干燥条件下轻轻刷毛的缺口表面，以在普通混凝土基底表面（NCSS）和UHPFRC之间成功粘结。然后，在受损试样周围铸造厚度为30mm的新鲜UHPFRC护套。整个测试矩阵由三个1/3比例的受损外部BCJ组成，具有不同的柱轴向载荷（CAL）。用UHPFRC修复这些试样，并在单调荷载下重新测试。根据实验结果，修复后的试件在荷载-位移响应、最大强度、位移延性、初始刚度、割线刚度和耗能能力方面与原始状态下测试时记录的相应值相比，表现出优异的性能。这种康复干预不仅恢复了严重损伤标本的强度、刚度、延展性和能量耗散能力，而且提高了它们的性能。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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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