title: The role of iron in sulfide induced corrosion of sewer concrete.
abstract: The sulfide-induced corrosion of concrete sewer is a widespread and expensive problem for water utilities worldwide. Fundamental knowledge of the initiation and propagation of sewer corrosion, especially the interactions between chemical reactions and physical structure changes, is still largely unknown. Advanced mineral analytical techniques were applied to identify the distribution of corrosion products and the micro-cracking that developed along the corrosion boundary. It was found that sewer concrete corrosion caused by reactions with sulfuric acid progressed uniformly in the cement of concrete. In contrast to conventional knowledge, iron rust rather than gypsum and ettringite was likely the factor responsible for cracking ahead of the corrosion front. The analysis also allowed quantitative determination of the major corrosion products, i.e., gypsum and ettringite, with the latter found closer to the corrosion front. The conceptual model based on these findings clearly demonstrated the complex interactions among different chemical reactions, diffusion, and micro-structure changes.
authors: Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia.
authors: Guangming
authors: G
authors: Jiang
authors: Sustainable Minerals Institute, Julius Kruttschnitt Mineral Research Centre, The University of Queensland, Indooroopilly, QLD 4068, Australia.
authors: Elaine
authors: E
authors: Wightman
authors: Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia.
authors: Bogdan C
authors: BC
authors: Donose
authors: Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia.
authors: Zhiguo
authors: Z
authors: Yuan
authors: Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia.
authors: Philip L
authors: PL
authors: Bond
authors: Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia. Electronic address: j.keller@awmc.uq.edu.au.
authors: Jurg
authors: J
authors: Keller
mesh_terms: D003252:Construction Materials; D003343:Corrosion; D004323:Drainage, Sanitary; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D008903:Minerals / Q000032:analysis; D008962:Models, Theoretical; D012722:Sewage / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
chemical_list: D008903:Minerals; D012722:Sewage; D013440:Sulfides; D007501:Iron
keywords: Corrosion; Cracking; Hydrogen sulfide; Iron; Mineral liberation analysis; Sewer