Experimental study on full scale steel-concrete composite beams using truss-type shear connectors

This paper presents an experimental study of full-scale steel-concrete composite beams using truss-type shear connectors. The connector geometry is original and effective. It is made from traditional steel rebar used in reinforced concrete structures. When compared with the stud-shear connector, the truss-type shear connector has several advantages, including low cost, ease of installation, and high resistance, among others. Previous research on the truss-type shear connector has made use of the popular push-out test, a reduced-scale physical model. However, for a better understanding of the truss-type shear connector behavior and to make it reliable for engineering practice, the truss-type shear connector must be studied under more realistic working conditions. In that sense, this research presents an experimental study in which three full-scale tests of steel-concrete composite beams, using truss-type shear connectors, are carried out. In the experimental program, different shear connection degrees are considered. The experimental results showed that when the shear connection degree is decreased, there is a rise in slippage between the steel beam and the concrete slab and a drop in the ultimate load. In the tests, the measured values of the uplift separation between the steel beam and the concrete slab were in compliance with the Eurocode-4 specifications. The failure modes of the specimens were characterized by excessive yielding of the steel beam or by a combination of this and the failure of the connections. The resistance of the truss-type shear connector was successfully predicted using the equation developed by the authors.