Distribution of corrosion and pitting factor of steel in corroded RC beams

• Corrosion process is studied under sustained loading.
• Corrosion results of natural process and then corresponds to in-situ conditions.
• Corrosion distribution is highly stochastic.
• Pitting factor is an important characteristic of corrosion distribution.

The purpose of this work was to study the corrosion distribution along a steel bar in beams of sizes typically used in the construction industry and the ratio between maximum cross-sectional loss and average cross-sectional loss of the steel bar. This work was based on three beams exposed to accelerated natural corrosion for 19–36 months. The cracking maps and crack widths were recorded. After the steel bars had been extracted from the beams and cleaned with Clarke’s solution, cross-sectional losses were measured. The experimental results show that average cross-sectional loss of the steel bar correlated well with maximum corrosion crack width. The pitting factors of steel bars were mainly between 2.5 and 5.0, and decreased with the increase of average cross-sectional loss. More measurements would be desirable in further research on the pitting factor before this factor is used for predicting the residual mechanical performance of corroded structures.