Study on shear performance of discontinuous PBL connectors with double holes

Abstract

Discontinuous perfobond rib shear (PBL) connectors can be applied to fabricated steel-concrete composite beams. In this paper, six push-out specimens were designed to explore the shear performance of PBL under static and repeated loads. Four specimens were used for static push-out test. The remaining two were used for fatigue push-out test. The static load test mainly considers the influence of concrete at steel plate end and post-cast strip on the shear bearing capacity, initial shear stiffness and load-slip curve of discontinuous PBL shear connectors. On the basis of the test results, the calculating formulas of the shear capacity and shear stiffness of discontinuous PBL connectors considering the influence of end bearing, bond group effect and post-cast strip are proposed. The predicted results of the formula are close to the experiment. From the fatigue test results, it is found that the fatigue performance of above specimens with C50 and UHPC is better than that with studs, but the fatigue resistance of discontinuous PBL connectors with UHPC is not increased in proportion to the shear capacity. In addition, the residual slip and shear stiffness of PBL specimens after cyclic loading are related to fatigue load amplitude.