Deflection of RC beams under simultaneous load and steel corrosion

This paper presents the results of a series of tests aimed at characterisin g the serviceability and ultimate limit state deflection of reinforced conc rete beams subjected to steel corrosion while under load. Reinforcement cor rosion was accelerated by impressing a DC current on the main tension steel while the load was applied through a static, spring-loaded support frame. Central deflections of beams subjected to 23% and 34% of the design ultimat e load, under 4-point loading over a span of 1050 mm and accelerated corros ion, were monitored over a period of approximately 30 days. These beams wer e then tested to failure to assess the effects of reinforcement corrosion o n performance at the ultimate limit state. Uncorroded beams were used as co ntrol samples and tested in parallel with the corroded samples. The results show the importance of assessing the structural effects of reinforcement c orrosion under simultaneous load and corrosion conditions, as would occur i n situ. In this situation, when 6% of the mass of steel is corroded, beam d eflections are increased by between 40% and 70% relative to the deflection of the control samples. Furthermore, depending on the extent of corrosion a nd the mode of failure, the ultimate bending strength of the beams can be r educed by up to 30%.