Research Abstract
Recently, much research efforts has been directed towards investigating the shear behavior of concrete beams reinforced with fibre reinforced polymer (FRP) bars. However, there is still a demand for more studies to solve this issue, especially in the case of high strength concrete (HSC) members. This paper presents an experimental study about the shear behavior of HSC beams longitudinally reinforced with carbon fibre reinforced polymers (CFRP) bars. A total of thirteen simply supported HSC beams with or without steel stirrups were fabricated and tested under four-point monotonic loading until failure. A rectangular cross section of width (b=120 mm) and
effective depth (d=224 mm) is adopted for all beams. The main investigated parameters include the shear span-todepth ratio (a/d), the longitudinal reinforcement ratio (ρf %), the transverse reinforcement ratio (ρv%), and the longitudinal reinforcement type (conventional steel bars or CFRP bars). All beams were designed so that failure
would occur due to shear. The mode of failure, the cracking load, the ultimate shear strength, and the midspan deflection are presented. It was found that the shear failure of HSC beams reinforced with CFRP bars occurs without warning; this may be attributed to the low elasticity modulus of CFRP bars. Addition of longitudinal steel bars to the flexural reinforcement of the tested beams improved both their ultimate shear capacity and their ductility.
The ultimate shear capacity is basically dependent on a/d and ρv%.
