Service Life Estimation of Reinforced Concrete Structures Made Using Cr-bearing Rebars in Microcell Corrosion Environments

摘要

Reinforced concrete structures made using Cr-bearing rebars subject to microcell corrosion were assumed with the aim of developing Cr-bearing rebars having the required corrosion resistance in microcell corrosion environments. Their service lives were then estimated for each type of corrosion environment based on a microcell corrosion rate model, and requirements for Cr-bearing rebars to achieve a service life of over 100 years were calculated. As a result, the service lives of concrete structures reinforced with Cr bearing rebars were found to increase as the Cr content increased in all types of corrosion environments. Also, Cr-bearing rebars with Cr contents of not less than 11 % and not less than 7% ensured service lives of over 100 years in harsh and moderate chloride attack zones, respectively. In carbonation zones, a Cr content of not less than 3% was proven to provide corrosion resistance for over 100 years.