Experimental investigation on seismic performance of endplate composite joints to CFST columns

The aim of this research is to carry out pseudo-static tests and investigate the seismic behaviour of the endplate composite joints of concrete-filled steel tubular (CFST) columns using blind bolts. Four full-scale blind-bolted endplate composite joints of a reinforced concrete (RC) slab to circular or square CFST columns were subjected to lateral cyclic displacements. Thereafter, the data obtained were used to evaluate the seismic performance of the typical composite joints from many aspects, such as hysteretic response, strength and rigidity degradation, ductility and energy dissipation capacity. In addition, failure modes were summarized based on the test phenomena; the influence of the column section and endplate types on the seismic performance of the joints was discussed in detail. The findings of the experiment demonstrate that the blind-bolted endplate composite joints possess appropriate ductility and adequate energy dissipation and, through reasonable design, they can satisfy the anti-seismic requirements in most seismic zones.