Abstract
In UBRC piers, the additional high strength bars are installed to add and control the post-yield stiffness of the skeleton curve. The original concept is to use perfectly unbonded bars, but in terms of the construction works and cost, it is desirable to use the round conventional bars without unbonding treatment. In this study, in order to clarify the influence of bond characteristics of bars, cyclic loading is carried out. Also, by analysis for experimental specimen, the behavior of splitting the bonding between the bars and the concrete is analyzed. As the results, it is found that it is possible to realize the UBRC structure with the conventional round bars, if the bond splitting can be controlled.
