超高性能纤维增强混凝土薄腹板中钢销剪力键的抗剪性能  

Shear Behavior of Steel Dowel Shear Connector in Thin UHPFRC Web

作　　者：张程 李文光 龚文锋 贺耀北 沈秀将 Zhang Cheng;Li Wenguang;Gong Wenfeng;He Yaobei;Shen Xiujiang(Changsha Planning&Design Institute Co.,Ltd.,Changsha 410000,China;Department of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]长沙市规划设计院有限责任公司,湖南长沙410000 [2]湖南大学土木工程学院,湖南长沙410082

出　　处：《市政技术》2025年第3期36-45,共10页Journal of Municipal Technology

基　　金：国家自然科学基金项目(52108138);湖南省交通科技项目(202245);长沙市望城科技计划项目(KJ231020)。

摘　　要：钢销剪力键是一类抗剪性能优异的新型剪力键,与超高性能纤维增强混凝土(UHPFRC)结合能够进一步提升钢-UHPFRC组合梁的结构性能。为研究钢销剪力键在UHPFRC薄腹板构件中的抗剪性能,进行了一系列推出试验和有限元分析。试验中通过控制UHPFRC中钢纤维体积含量(0%,1%,2%,3%)改变其抗拉性能,从而研究UHPFRC抗拉性能对钢销剪力键抗剪性能的影响。采用改良螺旋线(MCL)形钢销直接插入UHPFRC薄腹板中进行推出试验,使用数字图像相关(DIC)系统记录整个加载过程中的应变和裂缝扩展。从破坏模式、裂缝行为、抗剪承载力和荷载-相对滑移曲线等方面对试验结果进行评估。此外,依据试验结果验证了有限元模型的适用性,并进行了结构受力分析。结果表明,UHPFRC的抗拉性能对钢销剪力键的抗剪性能具有显著影响;当UHPFRC不含钢纤维时(脆性材料),试件的破坏模式为UHPFRC过早出现脆性破坏,表现出较低的抗剪承载力和延性;随着钢纤维含量的增加(抗拉性能提升),试件的破坏模式为UHPFRC与钢销协同破坏,最终钢销屈服开裂,表现出较高的抗剪承载力和延性。最后,验证了考虑UHPFRC的抗拉强度的钢销剪力键抗剪承载力计算公式的准确性,预测结果与试验值吻合度较高。The steel dowel shear connector,characterized with excellent shear behavior,is a new generation of shear connector,which can improve the structure performance of steel-ultra-high performance fiber reinforced concrete(UHPFRC)combined with UHPFRC.In order to investigate the shear behavior of steel dowel shear connector in thin UHPFRC webs,a series of push-out tests and finite element analysis were conducted.In the experiment,the steel fiber volume contents(0%,1%,2%and 3%)of the UHPFRC were controlled to change the tensile properties.The influence of the UHPFRC tensile properties on the shear behavior was studied.The modified clothoid(MCL)shaped steel dowel shear connector was inserted directly in thin UHPFRC web.The Digital Image Correlation(DIC)system was used additionally to record the strain and cracking propagation on UHPFRC surface during the whole testing process.The test results were evaluated from the aspects of damage model,cracking behavior,shear capacity and load-relative slip curve.According to the results,the applicability of finite element model was verified and structure force was analyzed.The results indicate that the tensile properties of UHPFRC have a significant impact on the shear performance of steel dowel shear connectors;Without steel fibers(brittle material),the specimens exhibited premature brittle failure of UHPFRC,resulting in lower shear capacity and ductility;As the steel fiber content increased(enhanced tensile properties),the failure mode transitioned to a synergistic failure between UHPFRC and the steel dowel,ultimately leading to yielding and cracking of steel dowel with higher shear capacity and ductility.Finally,the accuracy of a shear capacity calculation formula for steel dowel shear connectors,considering the tensile strength of UHPFRC,was validated.The predicted results showed high agreement with the experimental values.

关 键 词：桥梁工程 抗剪性能 推出试验 钢销 UHPFRC 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]