It is predicted that not only longitudinal shear forces but pull-out forces are produced by the transverse bending moment in shear-connectors of composite two plate-girder bridges with long-span prestressed concrete slabs. We carrided out the loading test using Full scale test models, in which the height and position of the headed stud were chosen as parameters. This paper presents the stress produced in headed studs, PC slab and vertical stiffeners, and ultimate pull-outstrength of the stud. Based on the experimental results, we show the above stresses are affected by the connecting method and discuss a design method of the headed stud.
