体外预应力加固竖向开裂全尺寸PCT梁的受弯性能试验  

Experiments on the Flexural Behavior of Full-scale PC T Girders with Vertical Crack Strengthened by Externally Prestressed

作　　者：傅鹏飞 邓旭东 郭荣鑫[1,2] 袁博 余滔 FU Pengfei;DENG Xudong;GUO Ronxin;YUAN Bo;YU Tao(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming,Yunnan 650500,China;Yunan Key Laboratory of Disaster Reduction in Civil Engineering,Kunming,Yunnan 650500,China;Yunnan Provincial Institute of Highway Science and Technology,Kunming,Yunnan 650051,China)

机构地区：[1]昆明理工大学建筑工程学院,云南昆明650500 [2]云南省土木工程防灾减灾重点实验室,云南昆明650500 [3]云南省公路科学技术研究院,云南昆明650051

出　　处：《公路工程》2024年第6期42-48,共7页Highway Engineering

基　　金：云南省交通运输厅科技创新及示范项目(2022-48)。

摘　　要：为了解预应力混凝土T梁体外应力钢束加固效果及竖向开裂后剩余承载力。对1片未采取任何措施全尺寸预应力混凝土T梁和1片经过体外钢绞线加固后T梁进行抗弯试验对比。分别从试验现象、挠度、应变响应、剩余预压应力及裂缝等方面进行分析。结果表明:加固后试验梁在常规荷载试验荷载下,刚度有了近70%的提升,开裂后荷载持续增加情况下,抗弯刚度下降不明显;承载力有显著提升;钢筋、混凝土应变明显减小;预应力张拉后T梁竖向裂缝基本闭合。未加固梁的刚度、抗裂性略差,但仍然有足够安全储备。该方法可有效提高竖向开裂T梁抗弯刚度、抗裂性能以及承载力。The aim of this study is to investigate the reinforcing effect of externally prestressed steel strands on precast prestressed concrete T-girders and the residual load-carrying capacity after vertical cracking.The study compares the flexural test results of one full-scale precast prestressed concrete T-girder without any measures taken and one T-girder reinforced with externally prestressed steel strands.Various aspects are analyzed including experimental phenomena,deflection,strain response,residual prestress,and cracks.The results demonstrate that the reinforced test girders showed a significant 70%improvement in stiffness during conventional load testing.Furthermore,there was no notable decrease in stiffness as the load continued to increase after cracking.The bearing capacity also exhibited a significant improvement.Both steel strains and concrete strains decreased significantly.After prestressing,the cracks in the T-girders were effectively closed.The stiffness and crack resistance of unreinforced beams are slightly poor,but they still have sufficient safety reserves.This method effectively enhances the stiffness,crack resistance,and load-carrying capacity of T-girders with vertical cracks.

关 键 词：桥梁工程 体外预应力 破坏性试验 抗弯性能 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]