Shear strength of angle shear connectors in steel-concrete composite members

Abstract

Shear connector limits the lateral shear flow and resists vertical uplift forces at the steel-concrete interface and also helps to transfer earthquake forces between concrete slab and steel beams. This study aims to conduct experimental investigations with a view to determine the shear strength of angle shear connector under monotonic loading. The investigation has been made through the push-out test with sixteen specimens. Effect of concrete compressive strength, connector embedded orientation, size and cutting length of shear connector on shear capacity of composite beam has been investigated in this experiment. The main test results have been presented in the form of load-slip curves followed by discussion on the failure modes, ultimate shear capacity, ductility and slip of shear connector at the steel concrete interface. Connector shear fracture is only type of failure observed in the test. For all the test specimens failure was initiated by cracking of concrete followed by shearing of angle connector. The push out test specimens with toe welding connections has larger ultimate capacity and less ductility than the specimens with heel welding connections. For larger size angle with 50 MPa concrete strength toe connected shear connector increased shear capacity by 143% comparing with heel connected shear connector. For lower size angle this increment is 74%. Concrete strength has a significant effect on the shear resistance of angle shear connector. For Heel welding connectors increasing the concrete strength from 40 MPa to 50 MPa resulted in 71% increase in the ultimate load. The ultimate capacity also increases with the increase of connector size and cutting length. Additionally, the experimental results are compared with the capacity prediction equation for channel connectors in the AISC 360-16 specification. The AISC 360-16 equation for channel connectors was observed to predict the ultimate shear capacity of toe connected shear connectors with very good accuracy. However, AISC specification was found to overestimate the capacity of heel connected shear connectors. It is accepted that the equation given by Ros (2011) is more conservative only for the specimen which are embedded in the toe welding direction. The equation proposed by AISC codes and Ros predicts the connector strength more accurately than Kiyomiya.