PUSH-OUT EXPERIMENTAL STUDY ON BOND-SLIP BEHAVIORS OF PBL SHEAR CONNECTOR UNDER STATIC LOADING

PBL shear connector is a key structure as the connection of corrugated web and flange up and down in composite bridges. The bond-slip behavior of PBL connector is significantly important for connector design. In this paper, the development of PBL shear connector is presented, and four PBL shear connector push-out tests under static loadings are conducted based on its practical application in pre-stressed concrete box-girder with corrugated steel web, in such a way the influence of the web's thickness and the hole's dimension is investigated on the bond-slip behavior, ultimate bearing capacity and failure mechanism. The results show that, every specimen shows similar bond-slip trend and ductility; thicker web and bigger diameter of the hole yield greater ultimate bearing capacity. Meanwhile, the relationship between the load and horizontal displacement shows that, during the preliminary loading stage, the concrete slabs expand outwards under the transferred shear load, and then distinct slip happens to shear connectors and the concrete slabs move outwards a little with the load increasing. The strain development accords with the load transformation rules from the records of strain gauges on the web, the flange of shear connectors and the steel slab. Finally, the experimental and analytical results are compared and the main influence factors on the ultimate capacity are presented, as a result, a new formula is proposed.