CFRP环包加固RC梁柱边节点抗震性能试验研究  

Experimental study on seismic performance of RC exterior beam-column joints strengthened by annular CFRP sheets wrapping

作　　者：黄群贤[1,2] 刘洋[1,2] 施明峰 HUANG Qunxian;LIU Yang;SHI Mingfeng(College of Civil Engineering,Huaqiao University,Xiamen 361021,China;Key Laboratory of Structural Engineering and Disaster Prevention of Fujian Province,Huaqiao University,Xiamen 361021,China)

机构地区：[1]华侨大学土木工程学院,福建厦门361021 [2]华侨大学福建省结构工程与防灾重点实验室,福建厦门361021

出　　处：《建筑结构学报》2022年第8期76-85,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51878304);福建省自然科学基金项目(2016J01240)。

摘　　要：传统CFRP加固钢筋混凝土梁柱节点技术无法克服正交梁空间障碍,难以对节点核心区形成有效横向约束,且易出现CFRP端部锚固失效,影响加固效果。引入金刚石绳锯切割技术,实现对节点核心区CFRP布的环包黏贴加固。为验证该加固方法的可行性和有效性,进行5个RC梁柱边节点试件在水平低周往复加载下的抗震性能试验,对试件的破坏特征、滞回性能和耗能能力等抗震性能指标进行分析,并将加固试件与未加固试件和“强节点”试件进行对比分析。试验结果表明:该加固方法显著提高了节点核心区受剪承载力,抑制节点核心区斜裂缝发展,实现破坏位置转移和破坏形态改变,加固后试件的破坏形态由节点核心区的脆性剪切破坏转变为梁端延性弯曲破坏,试件的承载能力、延性和耗能等抗震性能指标均得到明显提高,且加载过程中加固试件CFRP布未出现搭接锚固失效或界面剥离,加固效果显著,验证了CFRP环包加固技术的可行性和有效性。在试验和理论分析的基础上,提出了CFRP环包加固RC梁柱节点核心区斜截面承载力计算式,能较好地预测加固RC框架节点斜截面承载力。Owing to the issue of space obstacle of the orthogonal beams, the traditional strengthening technology for reinforced concrete(RC) beam-column joint with CFRP sheets cannot generate effective lateral constraints on the core area of the joint and is prone to anchor failure, resulting in negative impacts on the strengthening effect. In this paper, a diamond wire saw cutting technology was adopted to achieve an annular wrapping of the joint core area with the CFRP sheets. To verify the feasibility and effectiveness of the proposed strengthening technology, five exterior joint specimens were tested under low cyclic reversed loading. The seismic performance, including the failure characteristics, hysteretic performance, and energy dissipation, was evaluated for all the specimens. The seismic performance of the strengthened joint specimens was compared with that of the specimens without strengthening and ‘strong joint’ specimens. It is indicated that the proposed annular CFRP sheets wrapping technology improves the shear bearing capacity of the joint core area, inhibits the development of diagonal cracks in the joint core area, and achieves the transfer of failure location and the change of failure mode. After strengthening, the failure mode of the specimens changes from brittle shear failure in the joint to ductile flexural failure at the end of the beam. As a result, the seismic performance, including the bearing capacity, ductility, and energy dissipation of the strengthened specimens is significantly improved. Additionally, during the loading process, no anchor failure or interface debonding occurs at the CFRP sheets, and the strengthening effect is significant. The test results verify the feasibility and effectiveness of the annular CFRP sheets wrapping strengthening technology. Based on the test results and theoretical analysis, formula for calculating the bearing capacity of the inclined section of the RC beam-column joint core strengthened by annular CFRP sheets wrapping was developed, which can well predic

关 键 词：RC梁柱边节点 节点核心区 CFRP布 抗震加固 低周往复加载试验 抗震性能 

分 类 号：TU375.403[建筑科学—结构工程]