Effect of Concrete Strength, Arrangement/Ratio of Reinforcement on Flexural Behavior and Cracking of Concrete Beams Reinforced with GFRP Bars

Abstract

Fiber reinforced polymers (FRP) are the safe alternatives to steel bars in reinforced concrete members in a humid environment. They have a very high durability against corrosion, especially in the extreme weather conditions. As a result of the low modulus of elasticity of these bars compared to the steel bars, the deflection and crack width are high in the beams reinforced with these bars. In this paper, the flexural behavior and cracking of concrete beams reinforced with GFRP bars are investigated. Twelve reinforced concrete beams with the cross-section of 250 × 250 mm and length of 2200 mm were manufactured and tested in a four-point bending setup. Eight beams were made with low reinforcement ratio, 4 of which were made of high-strength concrete and 4 were made of normal-strength concrete. In addition, 4 other beams were made with high reinforcement ratio made of normal-strength concrete. The parameters studied in this research are concrete strength, tensile bars arrangement and reinforcement ratio. The results show that the change in the strength of concrete as well as the change in the arrangement of tensile bars and reinforcement ratio lead to a change in the flexural behavior of the beams and also affect the cracking. Moreover, the experimental results are compared with the values predicted by ACI440.1R code.

Keywords

• rc beams
• flexural behavior
• cracking
• gfrp reinforcing bars
• concrete strength
• bars arrangement
• reinforcement ratio