摘要
为研究T梁体外预应力钢束加固效果,本文对一片经体外预应力加固的长周期在役40m预制T梁进行破坏性试验。分别从试验现象、试件荷载-挠度曲线、试件应变响应等方面对加固效果进行了分析。结果表明:随着荷载的增加,试件在L/3~2/3L马蹄、腹板处分别出现了少量的竖向、斜向裂缝,至加载结束时马蹄处竖向、腹板斜向裂缝间距大约分别为13cm、19cm。加固后试验梁,工况1(设计极限)加载挠度减小大约85.74%,工况2(实际极限)极限载荷增加近50%,表明体外预应力加固效果较好。加固之后,截面中性轴上移,在设计荷载39.73%,60.27%时应变发生突变,截面开裂。本文的试验及分析结果可为使用体外预应力加固方法的T梁承载能力评估及使用过程中病害控制提供借鉴。
In order to study the effect of external prestressed rigid beam strengthening of T beams,a long-term in-service 40-meter prefabricated T-beam reinforced with external prestressing is subjected to destructive tests.The reinforcement effect is analyzed from the aspects of test phenomenon,load-deflection curve of specimen,and strain response of specimen.The results show that with the increase of the load,a small number of vertical and diagonal cracks appear at the horseshoe and web of L/3 ~ 2/3L,respectively,the pitch is approximately 13 cm and 19 cm,respectively.After strengthening the test beam,the load deflection of the working condition 1(design limit) is reduced by about 85.74%,and the limit load of the working condition 2(actual limit) is increased by nearly 50%,indicating that the external prestressed reinforcement effect is better.After strengthening,the neutral axis of the cross section moves upwards,the strain suddenly changes at the design load of 39.73% and 60.27%,and the cross section cracks.The test and analysis results in this paper can be used as reference for the evaluation of the bearing capacity of T-beams using external prestressing reinforcement methods and the disease control during use.
作者
郑永瑞
武俊彦
许维炳
王来永
陈彦江
李娜娜
Zheng Yong-rui;Wu Jun-yan;Xu Wei-bing;Wang Lai-yong;Chen Yan-jiang;Li Na-na(Beijing Key Laboratory of Earthquake Resistant and Structural Diagnosis and Treatment,Beijing University of Technology,Beijing 100124,China;Institute of Highway Science,Ministry of Transport,Beijing 100191,China)
出处
《工程抗震与加固改造》
北大核心
2020年第6期151-157,共7页
Earthquake Resistant Engineering and Retrofitting
基金
国家自然科学基金青年基金项目(51908015,51978021)
国家重点研发计划资助项目(2017YFC1500604)
北京工业大学基础研究基金资助项目(004000546318524)
北京市教委科技计划一般资助项目(KM201910005020)。
关键词
预应力T梁
破坏性试验
体外预应力加固
承载能力评估
prestressed T beam
destructive test
external prestressed reinforcement
carrying capacity assessment
