Hysteretic behaviors of concrete-filled steel SHS beam-columns

Abstract

The use of concrete-filled composite columns has become increasingly popular in civil engineering. Much progress has been made on the research of the static behaviors of concrete-filled steel Square Hollow Section (SHS) columns; however, limited information is available on experimental behaviors of these columns when subjected to both axial and horizontal loading. In this chapter, two series of experiments are conducted. The specimens of the first series are short columns subjected to cyclic shearing force as well as constant axial force; whereas, the specimens of the second series are longer, mainly subjected to a combination of constant axial load and cyclically flexural loads. The main parameters varied in the tests are axial load ratio and tube width to thickness ratio. Compared to conventional reinforced concrete columns, the SHS specimens exhibit richer energy-dissipation characteristics. The moment capacities of SHS beam-columns can be predicted with reasonable accuracy from simplified interaction curves. In the chapter, the experimental load versus hysteretic defection relations are compared to those predicted by integral method presented earlier, and satisfactorily agreements are gained.