Findings of a 4 year study of concrete sewer pipe corrosion

Microbial induced corrosion (MIC) of reinforced concrete sewer piping and manholes is a significant issue in Australia and overseas costing water authorities hundreds of millions of dollars annually. It is anticipated that as the country's sewer infrastructure ages the problem will become more severe. Over the last 4 years an ARC and industry funded research project has been undertaken with the aim of building a mathematical model to predict the corrosion of concrete as a function of exposure time and environmental and operational conditions. After almost 4 years of field trials in Sydney, Melbourne and Perth sewers a detailed understanding of the evolution of the corrosion process has emerged and a phenomenological model has been developed. The present paper describes the study findings and their implication for pipe service life prediction.