钢-SFRC组合梁高强螺栓连接件受剪性能试验  

Experiment on shear behavior of high-strength bolt connectors in steel-SFRC composite beams

作　　者：汪威 张谢东[1] 张虹燕 陈甫君 白芳龙 郑鑫磊 唐宾朋 WANG Wei;ZHANG Xie-dong;ZHANG Hong-yan;CHEN Fu-jun;BAI Fang-long;ZHENG Xin-lei;TANG Bin-peng(School of Transportation and Logistics Engineering,Wuhan University of Technology,Wuhan 430063,Hubei,China;School of Engineering and Technology,University of New South Wales,Canberra 2600,Australia;PhaseⅡBranch,Hubei Qiaoxiao Expressway Management Co.Ltd.,Wuhan 432020,Hubei,China;Sichuan Transportation Construction Group Co.Ltd.,Chengdu 610041,Sichuan,China)

机构地区：[1]武汉理工大学交通与物流工程学院,湖北武汉430063 [2]新南威尔士大学工程与技术学院,澳大利亚堪培拉2600 [3]湖北硚孝高速公路管理有限公司二期分公司,湖北武汉432020 [4]四川省交通建设集团有限责任公司,四川成都610041

出　　处：《长安大学学报（自然科学版）》2023年第6期60-70,共11页Journal of Chang’an University(Natural Science Edition)

基　　金：四川交建集团科技项目(2021LSTJ4GC-001);国家建设高水平大学公派研究生项目(202206950055)。

摘　　要：为研究内置双螺母高强螺栓连接件在钢-钢纤维混凝土(SFRC)组合梁中的受剪性能,设计并制作4个推出试件进行推出试验,研究高强螺栓直径(M12、M16)、强度等级(G8.8、G10.9)及混凝土强度(CF25、CF30)对剪力件破坏形态、荷载-滑移曲线、荷载-混凝土板应变曲线、抗剪刚度以及抗剪承载力等力学性能的影响;结合试验结果与已有螺栓连接件受剪承载力计算式,提出内置双螺母高强螺栓连接件在钢-SFRC组合梁中的受剪承载力设计建议。结果表明:所有试件的破坏形态均为高强螺栓剪断破坏,并伴随螺栓下方混凝土的少量剥落;相比普通混凝土推出试件,掺入钢纤维能抑制混凝土板裂缝的产生和发展,并能提高试件的延性;内置双螺母高强螺栓连接件的典型荷载-滑移曲线由克服摩擦力阶段、初始滑移阶段、螺杆传力阶段、螺杆塑性阶段和破坏阶段组成;试件破坏时混凝土板的水平滑移量为1.17~2.05 mm,仅为钢梁-混凝土板竖向掀起滑移量的10.8%~26.0%;内置双螺母高强螺栓连接件的抗剪承载力和滑移后的抗剪刚度均随螺栓直径、强度等级及混凝土强度的增大而提高,初始滑移荷载随预紧力的增大而提高;内置双螺母高强螺栓连接件在SFRC推出试件中的峰值滑移量为5~12 mm,远大于其在普通混凝土板推出试验中的结果,从变形能力的角度建议SFRC组合梁中的高强螺栓直径应大于12 mm;提出的内置双螺母高强螺栓连接件抗剪承载力计算式与试验结果吻合较好,可为其在钢-SFRC组合梁中的设计提供参考。To investigate the shear performance of high-strength bolt connectors with double embedded nuts insteel-steel fiber concrete(SFRC)composite beams,four push-off specimens were designed and fabricated forconducting push-off tests.The effects of high-strength bolt diameter(M12 and M16),bolttensile strength(G8.8 and G10.9),and concrete strength(CF25 and CF30)on failure modes,load-slip responses,load-strain relationships of concrete slabs,shear stiffness,and shear bearing capacity were explored.Based on the test results andexisting design formulas,recommendations for bolt shear capacity were proposed.The resultsshow that boltshear-off is the primary failure mode in all specimens,accompanied by minor spalling of concrete under the bolt.Compared to push-off specimens with normal concrete,the addition of steel fiber effectively restrains theformation and propagation of cracks in concrete slabs,enhancing specimen ductility.The typical load-slip curvecomprises distinct stages are friction overcoming,initial slipping,bolt shank transferring,bolt yielding,and failure.Horizontal slip of the concrete slab ranges from 1.17 to 2.05 mm,representing only 10.8%to 26.0%of thevertical slip of the steel beam-concrete slab during specimen failure.Bolt shear capacity and post-slip shearstiffness increase with larger high-strength bolt diameter,greater bolt tensile strength,and higher concrete strength.The bolt's initial slip load rises with increased bolt preload.Peak slip in push-off specimens with SFRC variesfrom 5 to 12 mm,significantly exceeding the results obtained in push-off tests with normal concrete slabs.Therefore,it is recommended that high-strength bolt diameter in SFRC composite beams should exceed 12 mmfor adequate deformation capacity.The proposed design formula for bolt shear capacity aligns well with testresults,serving as a valuable reference for bolt design in steel-SFRC composite beams.4 tabs,9 figs,31 refs.

关 键 词：桥梁工程 高强螺栓连接件 推出试验 荷载-滑移曲线 受剪承载力 钢纤维混凝土 

分 类 号：U445.58[建筑科学—桥梁与隧道工程]