Comparison of two accelerated corrosion techniques for concrete structures

Characterizing deterioration of reinforced concrete structures caused by the corrosion of steel bars is a major problem in predicting service life. Normally, the galvanostatic method is used for accelerating steel bar corrosion in concrete. The surface characteristics of the corroded steel bar, however, are found to be different when the corrosion is induced by galvanostatic method or by natural environment. Recently, an artificial climate environment has been used to accelerate reinforcing bar corrosion in concrete. This method is becoming important in assessing the durability of concrete structures because of the similarity in surface characteristics of the corroded steel bar under natural and artificial climate environments. In this study, two groups of reinforced concrete beams were degraded as a result of the corrosion of steel bars. One group of beams was subjected to the galvanostatic method, while the other group was corroded using the artificial climate environment. Comparative studies including the corroded characteristics of steel bar surface, the mechanical behavior of the corroded bar, and the load-bearing capacity were conducted. The comparisons between the two groups of beams were based on the identical width of corrosion cracking. Obvious differences were found from the comparisons.