Influence of Pre-Load on Corrosion Vulnerability of Reinforced Concrete

The present study investigates the relation between loading and corrosion of reinforcing steel in reinforced concrete elements. Beam specimens of size 100 mm x 150 mm x 1200 mm were cast using three different normal and high strength concrete mixes. After 45 days of moist curing, these beams were subjected to four point bending at different loading levels. Some specimens were also subjected to cyclic flexural loads. After load tests, ponds were constructed on the tension side of these beams, and the specimens were subjected to ponding using 5% NaCl solution. Half cell potential readings were taken to monitor the time taken for corrosion initiation. After corrosion initiation, an external current was applied to these specimens to accelerate the corrosion process. The residual loading capacity of the beams was found at the end of the durability exposure tests. The results indicate that loading history and loading levels have significant effects on both corrosion initiation and corrosion propagation. The results also show that both corrosion initiation and propagation rates also depend on the type of concrete used.