开孔板连接件受剪性能试验研究

开孔板连接件是钢-混凝土组合梁中常用的一种抗剪连接件。通过21个开孔板连接件试件在单调静力荷载作用下的推出试验,研究了开孔板的开孔直径、混凝土强度等级、孔中横向贯通钢筋的直径和数量等对开孔板连接件的破坏形态、荷载-滑移特性和受剪承载力等的影响。研究表明:开孔板连接件的荷载-滑移曲线(P-S曲线)大致可分为弹性阶段、塑性发展阶段和下降段;提高混凝土强度等级、增大开孔直径可提高开孔板连接件的受剪承载力,横向贯通钢筋直径由16mm增大至20mm时,试件的受剪承载力提高了21.8%,配置横向贯通钢筋2 16的试件受剪承载力比相应的未配置横向贯通钢筋的试件高19.1%;随着混凝土强度等级的提高,试件抗剪刚度增大,而开孔直径及横向贯通钢筋直径则对抗剪刚度无明显影响。最后,基于试验结果提出了开孔板连接件受剪承载力的计算方法。研究成果可为编制《钢-混凝土组合桥梁设计规范》提供依据和参考。

Experimental studies on shear behavior of perfobond connectors

Perfobond shear connectors are commonly used as shear connectors in steel-concrete composite beams.This paper presents the results from static push-out tests on twenty-one perfobond shear connectors.The effects of the hole diameter of perfobond shear connector,concrete compressive strength,diameter and amount of the transverse rebar on the failure modes,load versus slip characteristics and shear resistance were mainly studied.Test results showed that the load versus slip curve of perfobond shear connectors approximately included the elastic stage,plastic-developing stage and the descending stage.Increasing the concrete compressive strength or hole diameter of the perforated steel plate could enhance the shear resistance of the perfobond shear connectors.When diameter of the transverse rebars increase from 16mm to 25mm,the shear resistance of the specimens is 21.8% higher.Shear resistance of specimens with transverse rebar(216) in holes is about 19.1% higher than that of specimens without transverse rebar in holes.The shear stiffness increased with high concrete strength.The connector hole diameter and the transverse rebar diameter have no obvious influence on the shear stiffness.In addition,this paper developed the formulas for calculating the shear resistance of the perfobond connectors.Achievements of the research can provide verifications and references for the compilation of the code for design of composite steel and concrete bridges.