2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Shahria Alam, University of British Columbia
Dr. Shamim Sheikh, University of Toronto
Use of deicing salt during harsh winter is a critical factor that causes substantial deterioration of concrete infrastructure. In order to improve the performance of concrete against corrosion, Fiber Reinforced Polymer (FRP) bars were introduced. However, the challenge lies in its brittle nature of failure. Hence, in a seismically active region, FRP rebars cannot be used as reinforcement in the critical regions of concrete structures (Plastic hinge) unless it can be jointly used with a ductile material. In this study, double reinforced section is introduced which will be named hybrid reinforcement. Longitudinal rebars will be arranged into exterior (FRP) and interior (steel) cages. Two layers of transverse reinforcements, either made from FRP (for exterior cage) or steel (for interior cage), are also provided. The prescribed hybrid reinforcement is one potential alternative to mitigate such a problem. Currently, limited research has been directed towards identifying the nonlinear behaviour of hybrid reinforced concrete bridge piers. Investigating the yielding capacity, post-peak stiffness and curvature ductility is important to understand the non-linear behavior of the hybrid section.
To achieve this objective, the behavior of hybrid bridge piers will be experimentally investigated under quasi-static lateral load and axial compression on a scaled-down (1:2) models. A finite element model will be developed and validated against experimental results. The seismic behavior of the studied hybrid bridge piers will depend on six factors, including the concrete strength, total reinforcement ratio, FRP/Steel reinforcement ratio, FRP / Steel cage diameter ratio, FRP transverse volumetric ratio, and Steel transverse volumetric ratio. In this study, a factorial analysis will be performed by considering the effect of these six factors and their interactions on the seismic behavior of hybrid bridge piers. The expected outcome of this research is developing a new design tool, for hybrid bridge piers, to determine the load-deflection relationship, energy dissipation capacity, and strains in the longitudinal and transverse reinforcements under combined normal and shear stresses.