الفهرس 
CHAPTER 1: INTRODUCTION CHAPTER 1: INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
A hybrid reinforcement system that combines steel and fiber-reinforced polymer (FRP) bars was proposed in this study as a solution to overcome the corrosion problem with a proper energy dissipation capacity. The study aims to develop a force reduction factor for concrete columns reinforced with hybrid reinforcement. Nonlinear finite-element analysis was used as a tool to achieve the research target. The study used a novel FEA model for reinforced concrete (RC) columns that has been previously published. The model can capture the behavior of concrete columns reinforced with steel or FRP bars. Eighty-five cases covering several combinations of steel and FRP reinforcements were studied. The studied parameters included the ratio between the effective GFRP reinforcement ratio and the balanced GFRP reinforcement ratio (the normalized reinforcement ratio), the replacement ratio, the confinement level, and the applied axial load. For completeness, the effect of fiber material (glass, carbon, and basalt) was also studied. The reported analysis results revealed that properly detailed hybrid RC columns have a recoverable and self-centering ability. The hybrid RC column sufficiently achieved the maximum drift meeting the limitation of most building codes. Furthermore, the specimens achieved satisfied levels of energy dissipation compared to the steel-reinforced column. The FRP material type was shown to have no effect as long as the mechanical characteristics are the same (Glass, and Basalt). Limiting the ultimate drift level in CFRP/steel RC columns at a lower margin compared to the GFRP and basalt /steel RC specimens is necessary to avoid failure. The envelope curves for the simulated specimens were bilinearly idealized. The elastic-plastic transition point and the maximum deformation limit were identified based on the seismic performance of the simulated specimens. The force modification factor was assessed and ranged between 2.74 to 3.83.