用于组合梁桥面板湿接缝的弧形钢筋连接构造  

Curved Bar Connection Configuration Used for Wet Joints of Deck of Composite Girder

作　　者：苏庆田[1] 胡一鸣 田乐[1] 曾明根 SU Qing-tian HU Yi-ming TIAN Le ZENG Ming-gen(School of Civil Engineering, Tongji University, Shanghai 200092, Chin)

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《中国公路学报》2017年第9期86-92,共7页China Journal of Highway and Transport

基　　金：国家重点基础研究发展计划("九七三"计划)项目(2013CB036303)

摘　　要：针对组合梁桥中预制桥面板在湿接缝处的受力特点和现有接缝处钢筋的连接形式,提出了一种构造简单、施工方便的新型的弧形钢筋连接构造。为了检验这种连接构造的力学性能,对其进行足尺模型的轴心受拉试验,并与现有的直钢筋连接方式和U形钢筋连接方式的力学性能进行试验对比,分析了3种湿接缝的开裂荷载、极限荷载、裂缝分布等。试验结果表明:弧形钢筋连接方式与直钢筋连接方式以及U形钢筋连接方式的湿接缝破坏形式相同,均是首先在干湿混凝土交界面上出现裂缝,3种钢筋连接方式的湿接缝对应的开裂荷载基本相同;随着荷载增加旧裂缝宽度增加、新裂缝相继出现,最后达到受拉极限状态时3种钢筋连接方式的湿接缝都是干湿混凝土交界面附近的钢筋达到屈服,此时接缝中部钢筋的应变为交界面处钢筋应变的1/2,且弧形钢筋连接方式湿接缝的抗拉极限承载力比其他2种略高;理论上在湿接缝区域中弧形钢筋连接方式的湿接缝其钢筋在厚度方向分布更加均匀,能在一定程度上提高承载力,通过试验也证实了在控制混凝土裂缝宽度和试件的承载力方面弧形钢筋连接方式的湿接缝比其他2种连接方式略优,因此弧形筋连接方式运用于实际工程中是可行和可靠的。According to the mechanical characteristics of wet joints of prefabricated decks in composite girder bridge and the existing applications of bar connections at the wet joint, a new type of curved bar connection with the characteristics of simple structure and convenient construction was proposed. To examine its basic mechanical behavior, the tensile experiment of full-scale model was carried out under the axial force, whilst the mechanical behaviors between the straight bar connection type and U-shaped bar connection type was compared by experiments. The cracking load, ultimate load and crack distribution of three types of wet joints were analyzed. The results show that the failure mode of the wet joint of curved bar connection is the same as that of straight bar type and U-shaped bar type. All types of connections first cracked at the junction interface of the dry and wet concrete, and the corresponding cracking loads of the three types of wet joints were almost the same. With the increase of the load, the old cracks width increases, whilst new cracks appear in succession. Finally, the bars around the interface of dry- wet concrete yield, and the three types of wet joints reach to the limit state of tension. The strain of the bars in the middle part of the joint is half the bars at the interface, and the ultimate bearing capacity of the wet joint of curved bar connection is slightly higher than that of others. In theory, the distribution of the bars of wet joints connected with curved bars is more uniform in thickness direction. The bearing capacity can be improved to some extent. It is verified that the wet joint of curved bar connection is better than the other two types in controlling concrete crack width and the bearing capacity of the structure. So it is feasible and reliable to apply wet joints with curved bars connection to the project.

关 键 词：桥梁工程 湿接缝 试验研究 弧形筋 抗拉性能 组合结构 

分 类 号：U441[建筑科学—桥梁与隧道工程]