Experimental Analysis of CSC-type Shear Connectors Behavior under Direct Shear: Pry-Out Test (I)

The use of steel and concrete composite sections has been recorded since the early 1950s, mainly in Europe and North America, as pioneers in the industrial production of steel elements. These systems have become popular in the world due to the efficiency of structural behavior, where steel withstands tension and concrete develops its bearing capacity in compression, being essential for the installation of stress transfer elements at the interface, called shear connectors. Recently, the use of cold-formed steel sections (CFS) has been included as a cost-effective alternative in the construction of small and medium-sized buildings. In this way, it complements concrete elements, allowing the formation of highly efficient systems, mainly in flooring systems. In this research the experimental validation of the behavior of CSC-type shear connectors is proposed, configured by Hurtado & Molina (2020), which are applicable to these CFS-concrete configurations. Pry-out tests were carried out, initially proposed by Anderson & Meinheit (2005), where the axial tensile load is applied to the steel section. This alternative experimental proposal differs from traditional push-out tests, since compressive loads can generate local bucking in steel shapes, particularly in CFS sections. The experimental results were statistically analyzed, evaluating the incidence of the compressive strength of the concrete, the thickness of the steel profile, and the spacing between connectors on the bearing capacity of the composite system. As a result of the research, the design formulation for CSC-type shear connectors in CFS-concrete composite sections is proposed. Keywords: composite sections, CSC-type shear connector, cold-formed steel (CFS), design formulation