Corrosion of reinforced concrete with rebar exposed in corrosion chambers and pilot sewers

Abstract: Concrete corrosion is a major deteriorating process affecting sewer systems worldwide. Corrosion causes loss of concrete mass, cracking of sewer pipes and ultimately, structural collapse. The rehabilitation and replacement of corroded sewers involves high costs, thus the basic knowledge and constructive suggestions for corrosion control are highly needed. Although the problem of concrete sewer corrosion is well-recognized, the corrosion of reinforcing steel (rebar) embedded in concrete matrix, including the fundamental knowledge and also the method for corrosion control, is rarely investigated in literature. To fill in these knowledge and technology gaps, this study aims to enhance understanding of the corrosion mechanism of rebar, the microstructures of rust at the steel/concrete interface and their correlations with concrete cracking in reinforced concrete sewers. A combination of techniques, i.e. X ray tomography, MLA, EDS, and micro XRD is utilized. Further, the basic bioinformatics using pyrosequencing and the FNA effects on corrosion control will be also investigated via lab-scale and pilot-scale experiments. Collectively, this study provides innovative insights into sewer corrosion which is greatly beneficial for a more comprehensive understanding of the sewer degradation process.