Research On Shear Performance Of Steel Fiber Reinforced Concrete Rubber-sleeved Stud Composite Connection

The stud connectors are convenient for construction,easy to guarantee quality,and have good stress,which are widely used in steel-concrete composite bridges.For the steel bridge deck paving of the stud connectors and the steel-concrete joint section of the composite bridge,there are problems such as easy cracking,crushing and poor fatigue performance of the studs.The concrete has strong tensile and shear resistance,and the connectors are resistant to shear.The structural form of steel fiber reinforced concrete(Steel Fiber Reinforced Concrete,abbreviated as SFRC)stud-rubber composite connector with high bearing capacity,low shear stiffness and good fatigue performance.Taking SFRC strength grade,rubber sleeve height,stud diameter,and loading mode as parameters,using model test and finite element numerical simulation calculation method to analyze the force transmission mechanism between steel plate,SFRC,rubber sleeve and stud,and explain The shear failure phenomenon of the SFRC stud-rubber composite connector,and the shear stiffness,shear capacity,failure mode and influencing factors of the composite connector are explored;the calculation formula for the shear bearing capacity of the composite connector is proposed,and a preliminary establishment is made The design method of the connector.(1)With SFRC grade,stud diameter,rubber sleeve height,and loading mode as variables,a total of 7 groups of 16 specimens were made for indoor push-out tests,in which the volume of steel fiber was 0.8%,the stud height was100 mm,and the rubber sleeve The barrel thickness is 5mm.By observing the experimental phenomena and failure results,the shear capacity,peak slip,load-slip curve and shear stiffness were obtained.(2)The influence of SFRC grade,stud diameter and rubber sleeve height on the shear bearing capacity and shear stiffness of SFRC stud-rubber composite connector was studied.The results show that the shear capacity of composite connectors increases with the increase of SFRC grade,but the growth rate tends to be slow.The shear capacity was almost linearly correlated with the diameter of studs;Loading mode and rubber sleeve height have little effect on shear bearing capacity.The placement of rubber sleeve will increase the peak slip of stud connectors and reduce the shear stiffness of stud connectors.(3)Based on ABAQUS finite element software,the SFRC stud-rubber composite connector was modeled,and the stress analysis of the finite element simulation results was carried out.The simulation results were compared with the experimental results to verify the correctness of the finite element,and the simulation results were well matched with the experimental results.(4)Based on the fitting study of test data and finite element simulation,the calculation formula of shear bearing capacity for the composite connector is established,which provides the basis and reference for the design and application of the composite connector.It is of certain theoretical significance to carry out the research on the shear performance of the composite connector and preliminarily establish the design method of the composite connector for improving the design calculation theory of the connector.