Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 58 3 2026 05 22 Investigation of Structural Behavior in Hybrid Reinforced Concrete Frames with Steel and GFRP Bars Investigation of Structural Behavior in Hybrid Reinforced Concrete Frames with Steel and GFRP Bars 335 352 6094 10.22060/ceej.2026.24097.8258 FA Fahimeh Maleki Faculty of Civil Engineering. Semnan University. Semnan, Iran 0000-0003-3061-8461 Omid Rezaifar Faculty of Civil Engineering. Semnan University. Semnan, Iran 0000-0002-4753-7775 Ali Kheyroddin Faculty of Civil Engineering. Semnan University. Semnan, Iran 0000-0001-7802-2013 Journal Article 2025 04 24 The use of Fiber-Reinforced Polymer (FRP) bars as a solution to prevent corrosion in structures such as beams, slabs, bridges, and multi-story parking structures is gaining prominence. However, due to their linear-elastic behavior, brittle failure, and low modulus of elasticity, concerns have been raised regarding their structural performance. This study presents a numerical investigation into the behavior of ten one-story one-span reinforced concrete frames subjected to pushover analysis using ABAQUS software. The primary objective is to evaluate and compare the performance of frames reinforced with various types of FRP bars (in beams, columns, or both) against conventionally steel-reinforced concrete frames. The results indicate that using CFRP bars in a one-story frame increases the maximum lateral load and corresponding story drift by approximately 63% and 32%, respectively, compared to the steel-reinforced frame. Conversely, the use of GFRP and AFRP bars leads to a reduction in these parameters. Optimal performance was observed when GFRP and AFRP bars were used exclusively in the beams; in this configuration, the maximum lateral load increased by approximately 18% and 16%, respectively, compared to their use in the columns of the investigated hybrid frames. Furthermore, to examine the trend of crack initiation and propagation, the maximum plastic strain was compared at different drift levels. The use of Fiber-Reinforced Polymer (FRP) bars as a solution to prevent corrosion in structures such as beams, slabs, bridges, and multi-story parking structures is gaining prominence. However, due to their linear-elastic behavior, brittle failure, and low modulus of elasticity, concerns have been raised regarding their structural performance. This study presents a numerical investigation into the behavior of ten one-story one-span reinforced concrete frames subjected to pushover analysis using ABAQUS software. The primary objective is to evaluate and compare the performance of frames reinforced with various types of FRP bars (in beams, columns, or both) against conventionally steel-reinforced concrete frames. The results indicate that using CFRP bars in a one-story frame increases the maximum lateral load and corresponding story drift by approximately 63% and 32%, respectively, compared to the steel-reinforced frame. Conversely, the use of GFRP and AFRP bars leads to a reduction in these parameters. Optimal performance was observed when GFRP and AFRP bars were used exclusively in the beams; in this configuration, the maximum lateral load increased by approximately 18% and 16%, respectively, compared to their use in the columns of the investigated hybrid frames. Furthermore, to examine the trend of crack initiation and propagation, the maximum plastic strain was compared at different drift levels. https://ceej.aut.ac.ir/article_6094_ce5193a069bea027a60e06c57a106eb6.pdf