Effect of Geometric and Material Properties on the Behavior of Axially Loaded Concrete-Filled Stainless Steel Tube Columns

The application of concrete-filled stainless steel tubular (CFSST) columns has been increased rapidly in bridges and other infrastructure around the globe due to its greater corrosion resistance, fire resistance, and durability. This research has investigated the compressive behavior of CFSST columns both experimentally and numerically. An experimental program has been carried out with twenty-four (24) column specimens of six (6) different sizes and shapes with varying concrete strength. A 3D non-linear finite element model was developed to validate the experimental result. Besides, an extensive parametric study has been conducted to investigate the effect of geometric and material properties. It was observed that the numerical model can predict the experimental result and failure mode with very high accuracy. In general, the failure was occurred due to the outwards buckling of the steel tube. The ductility index decreased with increasing the compressive strength of concrete. The rectangular columns exhibited less ductility index than the square and circular columns. The increase in column axial capacity due to higher concrete strength was more significant for columns having a higher depth to thickness (D/t) ratio. Finally, the axial capacity of the columns was compared with the design standards.