Study on Concrete Filled Steel Tube Columns Reinforced with Diagonal Stiffeners

In modern day construction, the utilization of composite sections such as CFST columns has been enhanced due to their numerous advantages in construction processes. This study introduces a novel stiffening approach designed for use with unstiffened CFST columns using diagonal stiffeners. The diagonal stiffener used in this study is barbed wire with sharp thorn-like projections, aimed at reinforcing the bond between concrete and stiffener. The stiffeners can be arranged in binary, tertiary, and quaternary configurations. The study investigates the response of CFST columns with diagonal stiffeners under axial compression through an experimental investigation. The analysis concentrates on aspects such as ultimate capacity and deformation behaviour. Additionally, to assess the performance of the proposed stiffener arrangement, a finite element model were developed using ANSYS software and validated against experimental results. The study's findings demonstrated that, compared to unstiffened CFST sections, CFST columns strengthened with the suggested stiffening arrangements had an ultimate load capacity that was roughly 15–30% higher. The column section's strength increased and the local buckling of the exterior steel casing was removed. It was concluded that stiffened CFST columns improved the composite interaction between the infill concrete and the outer steel casing and provided better confining pressure on the concrete.