Concrete sewer pipe deterioration due to microbially-induced (biogenic) sulphuric acid (H2SO4) attack is not a new problem. Over the years, researchers have studied this phenomenon to establish the mechanisms involved and factors that influence the rate of concrete deterioration. Concrete is the most frequently used material for large diameter outfall sewers due to its inherent strength, durability under most conditions, and low costs of production. Furthermore, the fact that concrete pipes can generally be rehabilitated by application of inert or cementitious linings even when their steel reinforcement covers are corroded justifies the reason why they are preferred to other sewer pipe materials for use in wastewater disposal pipelines, bearing in mind the high costs that are associated with premature replacement of such deteriorated facilities. Notably, approximately 20% of the total damage of concrete sewer pipes in a given sewer section is caused by biogenic H2SO4 or sulphate (SO42-) attack [1].
