Fatigue and monotonic strength of RC beams strengthened with CFRPs

The overall deterioration of transportation infrastructure due to ageing and increasing traffic loads has motivated researchers to look for new ways of repairing and monitoring existing structures. Numerous studies were conducted and proved the efficiency of bonding fibre-reinforced polymers (FRP) systems on structural elements such as reinforced concrete (RC) beams and columns. Although there is a huge potential for the use of FRP materials, their large-scale implementation is often impeded by the lack of data on their durability when submitted to extreme loading conditions. This paper presents an experimental project undertaken in order to assess the durability of RC beams externally strengthened with carbon-fibre-reinforced polymers (CFRPs). The small-scale beams were loaded in fatigue for various numbers of cycles and then tested monotonically under four-point bending up to failure. Strain and stress curves are presented together with the ultimate loads and deflections obtained during testing. The test results provide an insight on the potential long-term performance of CFRP-strengthened beams submitted to severe fatigue loading conditions.