Abstract
This paper presents an experimental study on the dynamic strength and ductility of reinforced concrete bridge columns which are provided the lateral confinement with the interlocking spirals and cross ties. Three models with 900mm×400mm section and 1185mm high were constructed for the cyclic loading test. They were confined by ties (Type A specimen), ties as well as the cross ties (Type B specimen) and the interlocking ties (Type C specimen). In the Type C specimen, circular ties which were interlocked each other were used instead of the spirals. The Type B and Type C specimens failed in flexure while the Type A specimen failed in shear. The Type C specimen had superior strength and ductility to the Type B specimen. The shear strength was evaluated by comparing the design shear strength by five specifications and codes. Although some scattering was observed depending on the evaluation of strength carried by the concrete, the design shear strengthes provided in the specifications and codes were close to the experimental value.
