Advances in coatings and self-healing materials for concrete sewer infrastructure corrosion protection

The deterioration of concrete sewer infrastructure owing to bio-corrosion poses urgent and substantial structural, economic, and environmental challenges. Concrete sewer infrastructure is highly susceptible to microbiologically induced corrosion, primarily caused by biogenic sulfuric acid, which reduces durability and increases maintenance costs. This review presents a comprehensive overview of corrosion mechanisms in sewer environments, covering both traditional and novel preventive coatings that are widely used mitigation strategies to prevent corrosion. Various coating materials, both organic and inorganic, are explored, along with the usage of additives to improve chemical resistance, adhesion, and durability. Emerging techniques, such as self-healing and hydrophobic materials, are recognized for their ability to autonomously repair damage while limiting access to corrosive agents. The reliability of these protective systems is assessed using performance evaluation methods, namely chemical tests, microbiological tests, and field testing procedures. Furthermore, a comparative study is offered that takes into account the cost, environmental impact, and long-term performance of coatings, emphasizing the importance of such analyses in identifying the use in large-scale. The future directions emphasise the need for eco-friendly, cost-effective, and multifunctional protective solutions. Overall, this research demonstrates that combining improved coatings with self-healing technology is a potential approach to improve the service life, reliability, and sustainability of sewer infrastructure.