Corrosion Rate of Steel Bar at Joint and Its Control Method in Reinforced Concrete Members Induced by Carbonation

摘要

Recently, it has been reported that corrosion in reinforced concrete members can be attributed due to defects in construction such as joint. And concrete near the joint is easily penetrated by carbon dioxide and thus the steel bar becomes corrosive. However, there are only few researches that investigate the corrosion rate of the steel bars at the joint in carbonated concrete members. Therefore the following investigations are carried out in this study. First, to investigate the corrosion rate of the steel bar near the joint in carbonated concrete members in laboratory. Second, to investigate which control method, electrodeposition method or surface-sealing method, is effective to reduce the corrosion rate on the steel bar near the joint in carbonated concrete members in laboratory. And lastly, to verify the results of the first two objectives in existing reinforced concrete member induced by carbonation. In summary, it was shown that the corrosion rate on the steel bar generally becomes high at or under the joint. And it was confirmed that electrodeposition method was more effective' as control method for the reduction of the corrosion rate on the steel bar near the joint in carbonated concrete member than surface-sealing method.