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Modeling the structural effects of rust in concrete cover / Ioannis Balafas in Journal of engineering mechanics, Vol. 137 N° 3 (Mars 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 3 (Mars 2011) . - pp.175-185 Titre : Modeling the structural effects of rust in concrete cover Type de document : texte imprimé Auteurs : Ioannis Balafas, Auteur ; Chris J. Burgoyne, Auteur Année de publication : 2011 Article en page(s) : pp.175-185 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Corrosion  Cover  cracking  Pressure  Rust. Résumé : Vast governmental budgets are spent annually to face corrosion problems of steel reinforcement in concrete bridges attributable to the extensive use of deicing salts. Corrosion controls the lifetime of a bridge, which has two distinct periods. During the first period, chlorides diffuse through the cover. When sufficient chlorides are formed at the rebars, corrosion initiates. This marks the start of the second period, during which rust with higher volume to bare steel is produced. The rust puts pressure on the cover, which finally leads to cover spalling. In this paper, a model is developed to determine the time span of the second period. The model includes a volume compatibility condition that allows for the proper introduction of compaction of all materials that contribute to cover spalling, including the rust. A new condition for marking failure of the cover is also established, based on fracture mechanics and strain energies. Finally, a new formula is proposed for the rate of rust production, which allows for the constant rust production at early and nonlinear diffusion dependant rates at latter stages of corrosion. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i3/p175_s1?isAuthorized=no [article] Modeling the structural effects of rust in concrete cover [texte imprimé] / Ioannis Balafas, Auteur ; Chris J. Burgoyne, Auteur . - 2011 . - pp.175-185. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 3 (Mars 2011) . - pp.175-185 Mots-clés : Corrosion  Cover  cracking  Pressure  Rust. Résumé : Vast governmental budgets are spent annually to face corrosion problems of steel reinforcement in concrete bridges attributable to the extensive use of deicing salts. Corrosion controls the lifetime of a bridge, which has two distinct periods. During the first period, chlorides diffuse through the cover. When sufficient chlorides are formed at the rebars, corrosion initiates. This marks the start of the second period, during which rust with higher volume to bare steel is produced. The rust puts pressure on the cover, which finally leads to cover spalling. In this paper, a model is developed to determine the time span of the second period. The model includes a volume compatibility condition that allows for the proper introduction of compaction of all materials that contribute to cover spalling, including the rust. A new condition for marking failure of the cover is also established, based on fracture mechanics and strain energies. Finally, a new formula is proposed for the rate of rust production, which allows for the constant rust production at early and nonlinear diffusion dependant rates at latter stages of corrosion. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i3/p175_s1?isAuthorized=no