Concentrically loaded short high strength composite columns

This paper presents an experimental study on the concentrically loaded high strength square short concrete filled steel tube (CFST) columns. The nominal yield strength of the steel sections of columns was 690 MPa, and the unconfined compressive strength of the inner concrete section of the CFST columns had a range from 80 MPa to 100 MPa. Forty short specimens, with a length to width (L/b) ratio of 3.5 and a width to thickness ratio (b/t) of 15 to 40, were subjected to monotonic loading to investigate the ultimate strength, the local buckling effects and the confinement effects of the high strength CFST columns. The loading condition in the experiments presented herein only involved loading of composite columns and hollow section. The ultimate strengths of columns from the experiment were compared against the current international design standards which govern the design of composite columns.