Shear Performance and Calculation Model of Stud Connectors for Steel-SFRC Composite Beams

Abstract In order to explore the shear performance and calculation model of the stud connectors in steel - steel fiber reinforced concrete (SFRC) composite beams, push - out tests were carried out on six stud connectors, The effects that stud diameter, length, yield strength, tensile strength, and concrete type had on the shear performance of stud connectors were analyzed through the combination of test results and finite - element simulation. It is demonstrated by the results that the key shear failure pattern of the stud connectors is the shear fracture occurring at the bottom of the studs. The shear - bearing ability of the stud connectors is significantly influenced by the size of the studs. Compared with the stud connectors of 13 mm diameter, those with 16 mm and 19 mm diameters have an average increase of 54% and 77% in ultimate shear capacity, respectively. Compared with plain concrete specimens, SFRC specimens have higher shear capacity and stiffness but lower ductility. In the case of a high concrete strength grade, the studs are the primary determinants of the shear capacity of the connectors. Setting an appropriate effective length of the studs exerts a slight influence on the load - slip curve of the connectors. Boosting the yield strength and ultimate tensile strength of the stud material fails to remarkably improve the shear capacity or change the final slip. Under the stud shear failure mode, The exponential function fits well with the load - slip curve model. Additionally, the modified equation for calculating shear capacity can be applied to compute the shear capacity of stud connectors in steel - SFRC composite beams. The research can provide basis for engineering design.