Findings of a 7 Year Field Study of Concrete Sewer Pipe Corrosion

Paper No. 30
Mr Tony Wells1, Professor Robert Melchers1 – 1The University of Newcastle, Callaghan, Australia

Abstract

The degradation of reinforced concrete sewer piping via microbial induced corrosion (MIC) is a significant issue in Australia and overseas which costs water authorities hundreds of millions of dollars annually. Over the last 7 years an ARC and water industry funded research project has been carried out 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 7 years of field trials in Perth, Sydney and Melbourne sewers a detailed understanding of the how the corrosion process evolves over time under aggressive and more benign conditions has emerged and a phenomenological model has been developed which enables corrosion rates to be estimated once gas temperature, humidity and H2S levels are known. The study findings and their implication for pipe service life prediction will be discussed in detail.