预制拼装UHPC湿接缝模型拉伸试验  

Tensile Property Test of UHPC Wet Joints Model of Precast Segmental Bridge

作　　者：朱爱珠[1] 田知典 曾敏 胡方杰 孙远[1] ZHU Aizhu;TIAN Zhidian;ZENG Min;HU Fangjie;SUN Yuan(School of Civil and Hydraulic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;China Railway Construction Bridge Design and Research Institute,Wuhan 430063,China;China Railway Construction Co Ltd Bridge Engineering Laboratory,Wuhan 430063,China)

机构地区：[1]华中科技大学土木与水利工程学院,湖北武汉430074 [2]中铁建大桥设计研究院,湖北武汉430063 [3]中国铁建股份有限公司桥梁工程实验室,湖北武汉430063

出　　处：《土木工程与管理学报》2022年第1期7-13,共7页Journal of Civil Engineering and Management

基　　金：国家自然科学基金(52078230)。

摘　　要：针对目前常规湿接缝浇筑量大、钢筋连接复杂、易开裂等问题,提出一种构造简单、接缝混凝土浇筑量小的新型UHPC–锚固头钢筋湿接缝。为检验其连接性能,设计制作箱梁顶板UHPC–锚固头钢筋湿接缝拉伸试验模型共9个,通过拉伸试验研究裂缝形成、发展与破坏特征,探究了不同混凝土材料、钢筋布置与配筋率等参数对湿接缝模型力学性能的影响。研究结果表明:界面是湿接缝的薄弱部位,增加接缝配筋率可以显著提升抗拉极限承载力,并能有效延缓裂缝的扩展;锚固头钢筋交错搭接的构造能够明显加强接缝界面抗拉极限承载力,对其破坏形式有着显著影响;UHPC湿接缝在UHPC龄期较短时即可获得较高的承载力和延性,且随着UHPC龄期的增加接缝承载能力得以大幅提升。A new type of UHPC wet joint with staggered headed bars was proposed to solve the problems of excessive pouring volume, complex reinforcement connection and cracking defects of traditional wet joints. This UHPC wet joint is simple structured and needs a much smaller concrete pouring volume. 9 tensile test models of box girder roofs with wet joints were designed and fabricated to examine the connection performance of this new type of wet joint. The characteristics of cracking formation, extension and failure were studied. The influence of different concrete materials, reinforcement arrangement and reinforcement rate on the mechanical behavior of wet joint model were analyzed. The research results show that the bonding interface is the weak part of the joint. Increasing the joint reinforcement ratio can significantly improve the interface tensile bearing capacity and effectively delay the crack propagation. The staggered headed bar connection can significantly strengthen the ultimate tensile bearing capacity of the wet joint and have a significant impact on the failure mode. UHPC wet joint has the high bearing capacity and ductility even at a very young age, and the ultimate bearing capacity could be greatly enhanced by increasing UHPC age.

关 键 词：拼装桥梁 湿接缝 模型试验 超高性能混凝土 搭接钢筋 抗拉性能 

分 类 号：TU375[建筑科学—结构工程] U441[建筑科学—桥梁与隧道工程]