Experimental Investigation on Post-fire Response of Concrete-Filled Steel Tube Column Subjected to Elevated Temperature

Concrete-filled single steel tubular (CFT) columns are a form of composite member made up primarily of steel casings filled with concrete and are progressively employed as load-bearing parts nowadays. CFT columns have been used to build huge structures and long-span bridges in the construction field. The findings of an experiment on axially loaded concrete-filled single steel tubular columns that were post-heated as per the ISO 834 standard fire are presented in this study. The steel casings of diameters of 100 mm, 140 mm, and 180 mm with thicknesses of 3 mm and 6 mm were employed in the present study. Concrete of grade M30 was employed to fill the core of the columns. This research studies CFT columns' characteristics after exposure to temperatures ranging from 400°C to 1000°C. The test findings were compared to one another concerning the axial deformation against time, maximum load capacity, load-deformation pattern, ductility index, secant stiffness, and residual strength index. The experimental test findings were correlated to the results obtained from the provisions of codes including Eurocode-4, ACI, AS 5100, DBJ 13-51-2010, and GJB4142-2000.