{"title":"局部缩小横截面的 T 型钢筋混凝土梁试验研究","authors":"S.S. Zhang, D.D. Zhang, X.F. Nie, J.P. Ye","doi":"10.1016/j.istruc.2024.107180","DOIUrl":null,"url":null,"abstract":"The principle of strong column and weak beam (SCWB) is often adopted in the design of reinforced concrete (RC) frames to ensure their optimum seismic performance. However, insufficient consideration of the SCWB hierarchy has resulted in numerous existing RC frames violating such a hierarchy. Consequently, a novel seismic retrofitting technique (section reduction technique) was proposed for RC frames that violate the SCWB hierarchy. The section reduction (SR) technique involves creating a locally reduced cross-sections (i.e., a gap) in the bottom region of the beam (i.e., the compression region of the beam under negative bending) adjacent to the beam-to-column joint and applying a fiber-reinforced polymer (FRP) strengthening system, which reduces the negative bending capacity of the beam while improving the shear capacity of the gap region. Nine full-size RC beams were fabricated and three-point negative bending experiments were conducted to demonstrate the validity of the SR technique. Based on the test results, it was found that a gap of appropriate size can effectively reduce the negative bending capacity of a T-shaped RC beam. In addition, the ductility of the beams can be ensured if the occurrence of FRP U-jacket debonding can be effectively prevented when applying the FRP strengthening system.","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Experimental study on T-shaped reinforced concrete beams with locally reduced cross-sections\",\"authors\":\"S.S. Zhang, D.D. Zhang, X.F. Nie, J.P. Ye\",\"doi\":\"10.1016/j.istruc.2024.107180\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The principle of strong column and weak beam (SCWB) is often adopted in the design of reinforced concrete (RC) frames to ensure their optimum seismic performance. However, insufficient consideration of the SCWB hierarchy has resulted in numerous existing RC frames violating such a hierarchy. Consequently, a novel seismic retrofitting technique (section reduction technique) was proposed for RC frames that violate the SCWB hierarchy. The section reduction (SR) technique involves creating a locally reduced cross-sections (i.e., a gap) in the bottom region of the beam (i.e., the compression region of the beam under negative bending) adjacent to the beam-to-column joint and applying a fiber-reinforced polymer (FRP) strengthening system, which reduces the negative bending capacity of the beam while improving the shear capacity of the gap region. Nine full-size RC beams were fabricated and three-point negative bending experiments were conducted to demonstrate the validity of the SR technique. Based on the test results, it was found that a gap of appropriate size can effectively reduce the negative bending capacity of a T-shaped RC beam. In addition, the ductility of the beams can be ensured if the occurrence of FRP U-jacket debonding can be effectively prevented when applying the FRP strengthening system.\",\"PeriodicalId\":48642,\"journal\":{\"name\":\"Structures\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2024-09-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Structures\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://doi.org/10.1016/j.istruc.2024.107180\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, CIVIL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Structures","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.istruc.2024.107180","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
引用次数: 0
摘要
钢筋混凝土(RC)框架的设计通常采用强柱弱梁(SCWB)原则,以确保其达到最佳抗震性能。然而,由于没有充分考虑强柱弱梁的层次结构,导致许多现有的 RC 框架违反了这一层次结构。因此,针对违反 SCWB 层次结构的 RC 框架,提出了一种新的抗震改造技术(截面缩小技术)。截面减小(SR)技术包括在梁与柱连接处附近的梁底部区域(即负弯下梁的压缩区域)创建局部减小的截面(即间隙),并应用纤维增强聚合物(FRP)加固系统,从而减小梁的负弯承载力,同时提高间隙区域的抗剪承载力。为了证明 SR 技术的有效性,我们制作了九个全尺寸 RC 梁,并进行了三点负弯曲实验。测试结果表明,适当大小的间隙可有效降低 T 型 RC 梁的负弯曲能力。此外,在应用玻璃钢加固系统时,如果能有效防止玻璃钢 U 型夹层脱粘,则可确保梁的延展性。
Experimental study on T-shaped reinforced concrete beams with locally reduced cross-sections
The principle of strong column and weak beam (SCWB) is often adopted in the design of reinforced concrete (RC) frames to ensure their optimum seismic performance. However, insufficient consideration of the SCWB hierarchy has resulted in numerous existing RC frames violating such a hierarchy. Consequently, a novel seismic retrofitting technique (section reduction technique) was proposed for RC frames that violate the SCWB hierarchy. The section reduction (SR) technique involves creating a locally reduced cross-sections (i.e., a gap) in the bottom region of the beam (i.e., the compression region of the beam under negative bending) adjacent to the beam-to-column joint and applying a fiber-reinforced polymer (FRP) strengthening system, which reduces the negative bending capacity of the beam while improving the shear capacity of the gap region. Nine full-size RC beams were fabricated and three-point negative bending experiments were conducted to demonstrate the validity of the SR technique. Based on the test results, it was found that a gap of appropriate size can effectively reduce the negative bending capacity of a T-shaped RC beam. In addition, the ductility of the beams can be ensured if the occurrence of FRP U-jacket debonding can be effectively prevented when applying the FRP strengthening system.
期刊介绍:
Structures aims to publish internationally-leading research across the full breadth of structural engineering. Papers for Structures are particularly welcome in which high-quality research will benefit from wide readership of academics and practitioners such that not only high citation rates but also tangible industrial-related pathways to impact are achieved.