Seismic behavior of blind bolted end plate composite joints to CFTST columns

The seismic behavior and failure mechanism of a novel type of composite joints are presented in this paper. These composite joints are composed of composite steel-concrete beams and square concrete-filled thin-walled steel tubular (CFTST) columns. The steel beams are connected to the CFTST columns using end plates with blind bolts, while the cast-in-situ RC slabs are attached to steel beams with shear connectors. Some quasi-static tests were performed on flush and extended end plate joints and horizontal cyclic displacements at the column ends were experienced during the test. A detailed account of the results and observations from the cyclic tests are investigated, and the main behavioral aspects are discussed. The seismic performance of the blind bolted composite joint to CFTST column is estimated in terms of the hysteretic behavior, strength and stiffness degradation, ductility, and energy dissipation capacity, etc. The results of this study show that the novel composite joints exhibit adequate ductility and energy dissipation, whilst they behave in a semi-rigid manner according to the EC3 specification.