Behavior of seawater sea sand concrete-filled plastic-lined steel tube stub columns under axial compression

Abstract

This study presents the experimental results of seawater sea sand concrete (SSC)-filled plastic-lined steel tube (SSC-PLST) stub columns subjected to axial compression. The concrete strength is set as the main test parameter, and the full-range behavior of SSC-PLST specimens is recorded in terms of failure mode, load-deformation response, load-carrying capacity, and law of stress-strain development. The experimental results show that all the SSC-PLST stub columns behave in a ductile manner, which is similar to the conventional concrete-filled steel tube (CFST) members. During testing, obvious axial deformation accompanied with outward local buckling in the plastic-lined steel tube is observed. The composite actions between the infilled SSC and plastic-lined steel tube are demonstrated through the analysis of load-carrying capacity and strain development. As the concrete strength increases, the SSC-PLST columns tend to have an increasing load-carrying capacity, but the corresponding ductility shows a downward trend. Finally, the ultimate load-carrying capacity of SSC-PLST stub columns is predicted using the calculation methods that are already available for conventional CFST members, and the efficiency is evaluated.