An experimental study of composite effect on the behaviour of beam-column joints subjected to impact load

Abstract

This paper presents an experimental study on structural behaviour of composite beamcolumn joints under a middle column removal scenario. Specimens were subjected to impact loads from an MTS drop-weight testing machine. Two joints with welded unreinforced beam flange and bolted web connections were designed per AISC 360-10. One of the beam-column joints had a thicker composite slab. The joints were restrained by pinned supports at two beam ends, which were connected to rigid A-frames to represent boundary conditions from adjacent structures. Test results indicated that the composite slab significantly affected the impact force due to an increase of inertia. However, other structural responses (especially displacement of the middle column) decreased due to increase of stiffness contributed by the thicker composite slab. The finding was that increasing thickness of composite slab can increase the resistance of composite joint significantly due to increased composite effect. More experimental studies were conducted to investigate other types of joints.