Experimental study of CFST column to steel beam bolted connection with curved end-plates

This paper presents results of experimental study of a bolted column-beam connection with an extended curved end-plate joining steel beam and a hollow core Concrete-Filled Steel Tube (CFST). Column concrete hollow core was formed by centrifugal casting process that allowed decreasing porosity, increasing homogeneity and strength of the concrete. It was expected that strength and stiffness of the joint would be significantly affected by spalling of the concrete core due to transverse action, which would limit rotation of the joint and bearing capacity of the column. However, the concrete hollow core had no prominent signs of fracture – bending strength of the joint was determined by punching shear of the steel tube wall. Further result analysis has shown that, in reference to Eurocode 3, the joint may be classified as semi-rigid and that non-uniform initial contact between the end-plates and the column can reduce stiffness of the joint. In addition to this, it has been found that the analytical Eurocode component method is in close agreement with the attained test results, but its feasibility should be validated against additional tests with other failure modes.