端锚CFRP网格U型箍加固RC箱梁抗弯性能试验  

End anchor CFRP grid U-hoop reinforced RC box girder bending performance test

作　　者：钟正强 刘珺 郭凯军 陈子慕 ZHONG Zhengqiang;LIU Jun;GUO Kaijun;CHEN Zimu(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,Hunan,China;Hunan Province Engineering Laboratory for Safety Control of Bridge Structures,Changsha University of Science&Technology,Changsha 410114,Hunan,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114 [2]长沙理工大学桥梁结构安全控制湖南省工程实验室,湖南长沙410114

出　　处：《建筑科学与工程学报》2025年第2期93-100,共8页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(52178186)。

摘　　要：为研究聚合物砂浆(PCM)-碳纤维增强复合材料(CFRP)网格U型箍加固钢筋混凝土箱梁在受弯过程中的界面机理和破坏模式,深入探究不同加固方式下的抗弯加固效果以及网格U型箍的受力情况,对5根箱形钢筋混凝土梁进行四点弯曲静力加载试验。结果表明:在使用CFRP网格U型箍进行端部锚固后,箱梁的抗弯承载力以及底部CFRP网格的抗拉利用率都有进一步提升,使用宽度为120 mm的45°斜向U型箍进行加固时,其抗弯承载力相比FT试件(仅在梁底部用纵向CFRP网格加固的试件)提升了18.4%,CFRP底部网格最大应变提升了93.1%;PCM-CFRP网格组合加固系统与钢筋的共同受力性能良好,能有效延后钢筋进入屈服阶段;当使用90°U型箍对箱梁进行端部锚固时,试件破坏模式为PCM-CFRP网格组合层与混凝土之间的中部剥离破坏,而45°斜向U型箍锚固加固的试件在同样的荷载下未出现中部剥离和受压区混凝土压碎的情况,说明其可有效遏制中部剥离破坏的出现;U型箍宽度越大,45°斜向U型箍加固效果越好,但90°U型箍加固的试件延性比45°U型箍加固的试件更好。In order to study the interface mechanism and failure mode of reinforced concrete box girder reinforced with polymer mortar(PCM)-carbon fiber reinforced composite material(CFRP)grid U-hoop reinforcement in the bending process,and to deeply explore the bending reinforcement effect and the force of the grid U-hoop under different reinforcement methods,four-point bending static loading test was carried out on five box-shaped reinforced concrete beams.The results show that after using CFRP grid U-hoop for end anchoring,the bending bearing capacity of the box girder and the tensile utilization rate of the bottom CFRP grid are further improved,and the bending capacity of 45°oblique U-hoop with a width of 120 mm is increased by 18.4%compared with that of FT specimen(specimen reinforced only with longitudinal CFRP grid),and the maximum strain of CFRP bottom grid is increased by 93.1%.The PCM-CFRP grid combination reinforcement system has good common force performance with the steel bar,which can effectively delay the steel bar into the yield stage.When 90°U-hoop is used to anchor the end of the box girder,the failure mode is the middle peel failure between the PCM-CFRP grid composite layer and the concrete,while the specimen reinforced with 45°oblique U-hoop anchorage does not have the middle peel and the crushing of concrete in the compression area under the same load,indicating that it can effectively limit the occurrence of middle peel failure.The larger the width of the U-hoop,the better the reinforcement effect of the 45°oblique U-hoop,but the ductility of the specimen reinforced with a 90°U-hoop is better than that of 45°U-hoop.

关 键 词：CFRP网格 U型箍 组合加固 钢筋混凝土箱形梁 抗弯试验 

分 类 号：TU375.1[建筑科学—结构工程]