The promising characteristics of Glass Fiber Reinforced Polymer (GFRP) bars including corrosion resistance, high strength to weight ratio, and excellent tensile strength have boosted their validity in construction sector. However, due to the different compressive and tensile strengths, there are still many uncertainties and challenges upon using GFRP bars as an effective substitution for steel reinforcement in reinforced concrete (RC) columns. Numerical analysis was performed using a nonlinear finite element software to investigate the seismic performance of GFRP-RC columns, under simultaneous axial and cyclic lateral loading and compare their cyclic behavior with that of hybrid- and steel-RC columns. The findings revealed that the steel-RC column exhibited the greatest capacity for energy dissipation; the Hybrid-RC and GFRP-RC columns dissipated 0.75 and 0.42 times as much energy as the steel-RC column, respectively. Moreover, when the residual displacement is below 1 % of the column length, the lateral deformation capacity of GFRP-RC columns and Hybrid-RC columns surpass steel-RC columns by 1.63 and 1.32 times. Therefore, among the three inspected cases, in terms of seismic performance, GFRP-RC column indicates the highest lateral deformation capacity without causing irreversible damage to the specimen. Additionally, by changing the composite stiffness ratio of the rebars from 0 to 1, the softening post-yield trend of the RC-columns can be interestingly transformed to a hardening behavior, which can lead to a change in the post-yield stiffness ratio of the column, from ???? 0.039 to 0.052. Given the substantial enhancement in seismic performance associated with an effective post-yield stiffness in columns, achieving hardening postyield behavior can be a unique characteristic for columns reinforced with varying percentages of GFRP bars.

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