Monotonic and cyclic behavior of densely confined concrete using stainless steel rings

This study suggests a dense lateral reinforcement for a Reinforced Concrete (RC) column whose spacing is smaller than the maximum gravel size. This study conducts axial compressive tests of concrete cylinders confined by dense reinforcement to verify the effectiveness of the dense lateral reinforcement. Stainless steel rings are used for the reinforcement since they are corrosion resistant. The dense reinforcing method with stainless steel rings successfully increases the peak strength of the concrete. The strains at the peak strength are much larger than those for the concrete confined by a conventional method with steel reinforcing bars. The failure mode of concrete densely confined by steel rings is due to the gradual fracture of each ring; the fracture of each ring reduces the stress on the concrete. The cyclic behavior of the densely confined concrete is similar to that of concrete confined by conventional steel reinforcement.