Experimental response of FRP reinforced members without transverse reinforcement: Failure modes and design issues

FRP reinforcement is well known as a possible alternative to steel bars in order to improve durability of
reinforced concrete members. However, the intrinsic brittleness of concrete and FRP materials may
induce problems at the ultimate conditions due to premature failure modes; the performance under
service loads is a critical issue as well. To investigate response of concrete members reinforced with
longitudinal glass or carbon FRP bars without shear reinforcement, an experimental program has been
developed. The sixteen specimens designed and cast within this project were characterized by different
study variables concerning cross section geometry, concrete grade and type of reinforcement. The results
of tests performed on FRP-reinforced specimens are presented in this paper. In particular, different failure
modes due to flexure and shear have been observed; response under load levels simulating service
conditions has been also examined. Results of FRP-reinforced specimens have been compared with those
given by control specimens provided with conventional steel bars. Finally, analytical procedures to
evaluate immediate deflections of FRP-reinforced members have been assessed.