Variation of steel loss and its effect on the ultimate flexural capacity of RC beams corroded and repaired under load

This paper presents results of an investigation on the variation of mass loss of deformed tensile steel bars in RC beams (153 × 254 × 3000 mm) that were corroded whilst under a sustained load using an impressed current, constant wetting cycles with 5% NaCl solution and two different drying cycles. Following the corrosion test, selected beams were patch repaired whilst under a sustained load, but eventually all beams were tested to failure. The results indicated that the highest level of corrosion occurred where there were longer drying cycles, and that the level of sustained load had little effect on the rate of corrosion. Maximum mass loss of steel was found to occur at the centre of the corrosion region. The ultimate flexural capacity of beams was found to be best related to the maximum gravimetric mass loss compared to the average mass loss of steel. A maximum mass loss of steel of 1% was found to reduce the flexural capacity of beams by 0.7%.