Pushout Tests on Headed Studs and PBL Shear Connectors Considering External Pressure

AbstractIn composite structures, the shear keys, that is, the headed studs or the perfobond rib shear connectors (PBL shear connectors), are typically subjected to external pressure, owing to the self-weight of the pavement and safeguards, for example. These loads may exert some influence on the shear behavior of such shear keys. To investigate the shear behavior of the headed studs and PBL shear connectors under external pressure, eight specimens were tested, and the slip-load curve and crack developments were obtained. According to the test results, the external pressure significantly contributed to the stiffness and strength of the headed studs owing to the friction effect. The relative improvement for the PBL shear connectors was not very obvious owing to its huge basic capacity. For the PBL shear connectors, the external pressure resulted in the slight relative enhancement of the load-carrying capacity regardless of the friction force. Employing the confining concrete strength improved the prediction of the PBL shear connectors, and the estimation error was reduced to less than 0.3%.