Circular Concrete-Filled Steel Tubes Subjected to Coupled Tension and Chloride Corrosion

This paper investigates the time-dependent behavior of concrete-filled steel tubular (CFST) tensile members subjected to coupled long-term loading and chloride corrosion. A series of experiments for CFST members under both 120-day sustained tensile load and electrically accelerated corrosion in chloride solution are conducted, with loading ratio and corrosion rate as the main parameters. A finite-element analysis (FEA) model is established and validated by the test data for the full-range analysis of CFST tensile members considering the long-term behavior of the core concrete as well as the corrosion of the outer steel tube. The FEA model then is used for further analysis on CFST tensile members, including the interface performance, interaction between the steel tube and the core concrete, load distribution mechanism through the cross section, and ultimate strength. Parametric studies also are conducted, based on which a simplified method is suggested for calculating the tensile strength of CFST members under coupled long-term loading and chloride corrosion. (C) 2017 American Society of Civil Engineers.