Behaviour of corroded reinforced concrete beams repaired with FRP sheets under monotonic and fatigue loads

In this study, the behaviour of corroded reinforced concrete beams repaired with FRP sheets under monotonic and fatigue loads was investigated. The study included an experimental program and analytical and finite element modelling.; FRP sheets were applied after the main reinforcing bars were corroded to an average of 5.5% mass loss. Following FRP repair, some specimens were tested immediately to failure. The other repaired specimens were subjected to further corrosion before being tested to failure, to investigate their post-repair (long-term) performance.; During the monotonic loading, the test specimens were subjected to two repeated loading cycles to investigate the performance of these specimens under repeated loading. A constant amplitude sinusoidal loading with a 1.7 Hz frequency was utilized for the fatigue loading tests. The lower and upper loading limits of the fatigue loading corresponded to 6 and 54 kN, respectively.; Experimental results showed that corrosion of the main reinforcing bars had a more detrimental effect on the fatigue performance than its effect on the performance under monotonic loading. This was due to formation of pits in the main reinforcing bars, that significantly reduced the fatigue life.; The experimental program included ancillary tests on thirty-six reinforced concrete prisms (152 x 254 x 270 mm), that were corroded using an electric current while exposed to wet-dry cycles in the corrosion chamber. Mass loss data for these prisms were used to derive an empirical formula for mass loss prediction.; The flexural response of unrepaired and FRP repaired corroded beams was predicted using an analytical model. This analytical model was based on evaluation of the residual bond strength after the exposure to corrosion. The beam analyzed was divided into cracked and uncracked sections, and the curvature was evaluated for each section. Then, a numerical integration was performed to calculate the deflections.; The fatigue loading results were analyzed using a strain-life approach. Equivalent fatigue notch factors were estimated for the main reinforcing bars of the specimens tested. Pits formed due to corrosion in the main reinforcing bars resulted in an increase in the equivalent fatigue notch factor.; The study showed that repair of corrosion damaged beams using FRP wrapping significantly reduced the cracking intensity due to corrosion. When FRP sheets were used for flexural strengthening, the performance under monotonic and fatigue loading was significantly enhanced. (Abstract shortened by UMI.)...