Shear capacity of concrete beams reinforced with fiber reinforced polymers

This paper evaluates the shear capacity of concrete beams and slabs reinforced with different types of fiber reinforced polymer (FRP) bars. The effect of the low modulus of elasticity and the non-yielding characteristics of the FRP bars on the concrete shear strength is discussed. Seven prototype concrete beams reinforced with glass fiber reinforced polymers (GFRP) and carbon fiber reinforced polymers (CFRP) were subjected to four-point loading up to failure. Steel stirrups were used as shear reinforcement in all beams. Measured shear capacities of the tested beams are compared with the values calculated according to the recently published procedures and codes for beams reinforced with FRP. Based on this investigation a simplified expression for the shear capacity of FRP reinforced concrete members is introduced. The proposed analytical method is also substantiated by test results available in the literature from eight concrete slabs and six concrete beams reinforced with conventional steel, GFRP, and CFRP bars. Good agreement was shown between the theoretical and the experimental results.