Shear Performance of GFRP Reinforced Concrete Beams Without Transverse Reinforcement

Volume 12 , Issue 2 , April 2026

Authors

Zhin Othman Ahmed Ahmed 1 ; Alan Saeed Abdulrahman Muhammed Abdulrahman 2

1 University of Sulaimani, College of Engineering, Civil Department, KR, Iraq

2 University of Sulaimani, College of Engineering, Civil Department, KR, Iraq

DOI logo 10.17656/sjes.10202

Keywords

Abstract

This study investigates the influence of glass fiber-reinforced polymer reinforcement bars on the shear capacity of simply supported concrete beams without web reinforcement and to investigate the dowel effect of this reinforcement. To determine the effects of concrete compressive strength, type of reinforcement, and reinforcement ratio on shear behavior, an experimental program was conducted on 12 beam samples, comprising six conventionally steel-reinforced beams and six beams. reinforced with GFRP bars. There were three different tensile reinforcement ratios (low, medium, and high) in each subgroup. Both the beams that have reinforced with GFRP or steel bars were designed to have theoretically the same tension forces (A_s F_y its equivalent from the GFRP properties) which resulted in comparable flexural capacity and two concrete compressive strengths. The experimental findings revealed that the shear capacity of GFRP-reinforced beams was approximately 36% less than that of steel-reinforced beams at low reinforcement ratios, 28% at intermediate reinforcement ratios, and 16% at high reinforcement ratios. And the enhancement of concrete compressive strength from 40 MPa to 55 MPa (38%) increased the shear capacity of GFRP-reinforced beams more significantly than that of beams reinforced with conventional steel. Also, the ACI code-440.11-22 formulae significantly underestimates the shear capacity, with an average ratio of experimental to predicted shear capacity of approximately 2.0 for both concrete compressive strength values that were chosen. 

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  • Published at12 April 2026

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