Experimental study and parameter analysis of L-shaped composite column under axial loading

A special-shaped column composed of concrete-filled steel tubes (SCFST column) is experimentally investigated in this paper. The SCFST column is composed of several small-sized concrete-filled square tubular columns (mono-columns) connected by connection plates. This kind of column is proposed because it can increase the usable space in residential buildings. The axial loading behavior of L-shaped SCFST columns is experimentally investigated. The failure mode, strain distribution, cooperation of mono-columns, bearing capacity, and the effect of a concrete core on column behavior were tested. As concluded, the SCFST column can be regarded as a useful kind of column. A finite element analysis model was proposed according to the experimental results, and the influence of connection plate size on bearing capacity was studied using the finite element model. Finally, proposed were the optimal width and thickness of connection plates for improving the design of the SCFST column.