Behavior of Steel Fiber-Reinforced High-Strength Concrete Columns under Different Loads

This paper reports the results of an experimental investigation program on the behavior of high-strength concrete (HSC) columns reinforced with micro, macro, and hybrid steel fibers. The specimens were tested under concentric, 25 and 50 mm (0.98 and 1.96 in.) eccentric axial and four-point bending. The main variables were the type, volume content and aspect ratio of steel fibers. Sixteen circular specimens of 205 mm (8.07 in.) diameter and 800 mm (31.49 in.) height were cast and tested. The specimens were reinforced with the same amount of longitudinal and helical steel reinforcements. It was found that the inclusion of either micro or hybrid steel fibers into HSC enhanced the strength and ductility of the specimens under eccentric axial loads. The results also showed that the addition of macro steel fibers into HSC enhanced the ductility but reduced the strength of the specimens compared to the specimens without steel fibers.