Postrepair fatique performance of FRP-repaired corroded RC beams: Experimental and analytical investigation

This paper presents the results of an experimental and analytical study of the fatigue performance of corroded reinforced concrete (RC) beams repaired with fiber-reinforced polymer (FRP) sheets. Ten RC beam specimens (152 X 254 X 3,200 mm) were constructed. One specimen was neither strengthened nor corroded to serve as a reference; three specimens were corroded and not repaired; another three specimens were corroded and repaired with U-shaped glass FRP sheets that wrapped the cross section of the specimen; and the remaining three specimens were corroded and repaired with U-shaped glass FRP sheets for wrapping and carbon-fiber-reinforced polymer (CFRP) sheets for flexural strengthening. The FRP sheets were applied after the main reinforcing bars were corroded to an average mass loss of 5.5%. Following FRP repair, some specimens were tested immediately to failure, while the other repaired specimens were subjected to further corrosion before being tested to failure to investigate their postrepair (long-term) performance. Reinforcement steel pitting due to corrosion reduced the fatigue life significantly. The FRP wrapping had no significant effect on the fatigue performance, while using CFRP sheets for flexural strengthening enhanced the fatigue performance significantly. The fatigue results were compared to smooth specimen fatigue data to estimate an equivalent fatigue notch factor for the main reinforcing bars of the tested specimens.