Flexural Behavior of Concrete Beams Reinforced with Carbon FRP and Steel Rebars

Hamza Ismael; Omar Qarani Aziz

doi:10.23918/eajse.v11i3p23

Authors

Hamza Ismael Civil Engineering Department, Salahaddin University-Erbil, Erbil, Iraq https://orcid.org/0009-0003-5495-3480
Omar Qarani Aziz Civil Engineering Department, Salahaddin University-Erbil, Erbil, Iraq https://orcid.org/0000-0002-6689-8146

DOI:

https://doi.org/10.23918/eajse.v11i3p23

Keywords:

Reinforced Concrete Beam, Crack Pattern, Flexural Behavior, Steel Bars, FRP Bars

Abstract

This research explores the flexural characteristics exhibited by concrete beams reinforced with either carbon fiber-reinforced polymer (CFRP) or conventional steel bars. A total of eight beams were cast, four reinforced with CFRP bars and four with steel bars, and were assessed using a four-point flexural testing method setup over an effective span of 2000 mm. Beams had a uniform height of 350 mm and a width of 150 mm to ensure a consistent reinforcement ratio. The beam designs followed the guidelines of ACI 440.1R-15 and ACI 318-19. Variables in the study were the reinforcement ratios relative to the balanced reinforcement ratio for FRP bars, and for steel, the ratio relative to the maximum allowable reinforcement. Bar type was considered a variable. Key parameters evaluated included the load at which initial cracking occurs, the maximum load the specimen can sustain, load-deflection behavior, and failure modes. Results indicated that beams reinforced with FRP bars exhibited greater deflection compared to those reinforced with steel. The ultimate load capacity was higher in steel-reinforced beams, suggesting greater stiffness of steel bars. CFRP reinforced beams (BSC) showed a greater number of cracks than the steel-reinforced beams (BSN); crack widths were wider in BSN beams than in BSC beams.

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