Pushout test on stirrup shear connectors in new steel concrete composite systems.

In structural engineering, composite construction occurs when two different materials are connected together so tightly that then operate as a single unit. The most common and important combination of construction materials currently is steel-concrete. This study was thus conducted to investigate the strength and behavior of the new shear connector created in steel-concrete composite systems. In such systems, the shear stirrups of the reinforced concrete beam are used as shear connectors, being passed through holes drilled in the web of inverted steel T-section that exists at the soffit of the beam. The program followed by this study thus tested a new arrangement of push-out specimens proposed for this purpose. A total of fifty-six push-out specimens were fabricated and tested to investigate the effect of multiple parameters on the shear strength and slip capacity of the shear connectors. The parameters studied in this experimental investigation were thus specimen dimensions (length and width), the diameter of the stirrups (shear connector), the number of connectors per specimen, concrete strength, type (size) of T-section, and shape of specimen. The experimental tests showed that the strength of connector is influenced significantly by various parameters. The strength of connector decreases with an increase in the number of connectors in the specimens, with the reduction in strength reaching 15% when three connectors are used instead of one. The strength of the connector increases with increases in the shear connector diameter, specimen width, and concrete strength, with such increase reaching 63%, 49%, and 25% respectively. The other parameters have little effect on the maximum shear strength of connector, however. [ABSTRACT FROM AUTHOR]