Axial Behavior of Concrete Filled-steel Tube Columns Reinforced with Steel Fibers

Concrete filled steel tube (CFST) columns are being popular in civil engineering due to their superior structural characteristics. This paper investigates enhancement axial behavior of CFST by adding fibers plain concrete that infill tubes. Four specimens were prepared: two square (100*100 mm) and circular (100 mm diameter). All 60 cm length. Plain mix reinforced with used columns. Ultimate load capacity, ductility failure mode discussed this study. The results showed the ultimate capacity increased 28% 20 % for columns, respectively. Also, exhibited better than confinement. Circular improved 16.3% 12%, local buckling which occurred near end while, mid-height. study involved sectional analysis captured very well. increasing fiber content 2% 51 38% Furthermore, doubling section size approximately 4 5 times