Behavior Of Reinforced Concrete Bridge Columns Having Varying Aspect Ratios And Varying Lengths Of Confinement PDF Download

To satisfy the aims of performance based design, levels of damage which interrupt the serviceability of the structure or require more invasive repair techniques must be related to engineering criteria. In this report, the influence of displacement history on performance limit states, the relationship between strain and displacement, and the spread of plasticity in reinforced concrete structures is explored. An experimental study is underway to assess the performance of thirty circular, well-confined, bridge columns with varying lateral displacement history, transverse reinforcement detailing, axial load, aspect ratio, and longitudinal steel content. Eight of these columns, with similar geometry and detailing, were subjected to various unidirectional displacement histories including standardized laboratory cyclic loading and recreations of the displacement responses obtained from non-linear time history analysis of multiple earthquakes with distinct characteristics. Longitudinal reinforcing bars were instrumented to obtain strain hysteresis, vertical strain profiles, cross section curvatures, curvature distributions, and fixed-end rotations attributable to strain penetration. Results indicate that bar buckling was influenced by load history, but the relationship between strain and displacement along the envelope curve was not. The main impact of load history on bar buckling is its influence on accumulated strains within the longitudinal reinforcement and transverse steel.