An Innovative Approach to Simulate Biocorrosion in Concrete Pipes

Concrete corrosion in wastewater concrete pipes is mainly caused by the diffusion of aggressive solutions and in situ production of sulfuric acid by sulfur oxidizing microorganisms, which affect the physicochemical properties of concrete. In this study, a novel pilot-scale experimental setup was designed to replicate conditions in sewage systems as well as the bacterial-induced corrosion process in concrete pipes. The reliability of this test was evaluated by conducting a flexural strength test on arch-shaped cement mortar specimens over a 6-month period. Quantitative assessments of the properties were carried out over the 6-month period, and the average corrosion rate of 3 mm/y with 73 % reduction in bending strength (of the initial strength) and an average weight loss of 15 % was observed in cement-based mortar specimens. The proposed methodology and the results provide a better understanding of the biocorrosion process and quantitative information on the performance and effectiveness of different pipe/coating materials, which is necessary in evaluating concrete pipe's durability.

Automated summary

A new pilot-scale experimental setup was designed to replicate conditions in sewer systems and bacterial-induced corrosion in concrete pipes, with quantitative assessments showing an average corrosion rate of 3 mm/y, 73% reduction in bending strength, and 15% weight loss in cement-based mortar specimens over a 6-month period.