Documents disponibles écrits par cet auteur

Concrete cracking due to chloride-induced reinforcement corrosion / R. Zhang in European journal of environmental and civil engineering, Vol. 16 N° 3-4 (Mars/Avril 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 3-4 (Mars/Avril 2012) . - pp. 402-413 Titre : Concrete cracking due to chloride-induced reinforcement corrosion : Influence of steel–concrete interface defects due to the ‘top-bar effect’ Type de document : texte imprimé Auteurs : R. Zhang, Auteur ; A. Castel, Auteur ; R. François, Auteur Année de publication : 2012 Article en page(s) : pp. 402-413 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Reinforced  concrete  Chloride  corrosion  Steel–concrete  interface  Cracking Résumé : This article deals with the influence of the steel–concrete interface condition on reinforcement corrosion and concrete cracking in a chloride environment. Four large concrete members were cast with horizontal reinforcements at different levels in order to create voids under the upper horizontal bars due to the well-known ‘top-bar effect.’ Then, the members were sawn into smaller specimens that included one rebar. Specimens obtained were submitted to wetting–drying cycles in salt water (natural corrosion process) until concrete cracking was observed. Results show that before concrete cracking, the corrosion pattern observed is completely different between the specimens with defect (generalised corrosion) or without defect (local pitting corrosion). The concrete cracking is delayed for specimens affected by the ‘top-bar effect’ in spite of a higher corrosion rate, and occurs at a significantly higher corrosion rate. A new model for uniform steel cross-section reduction calculation from concrete crack width in case of ‘Top-bar effect’ is proposed. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.667984 [article] Concrete cracking due to chloride-induced reinforcement corrosion : Influence of steel–concrete interface defects due to the ‘top-bar effect’ [texte imprimé] / R. Zhang, Auteur ; A. Castel, Auteur ; R. François, Auteur . - 2012 . - pp. 402-413. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 3-4 (Mars/Avril 2012) . - pp. 402-413 Mots-clés : Reinforced  concrete  Chloride  corrosion  Steel–concrete  interface  Cracking Résumé : This article deals with the influence of the steel–concrete interface condition on reinforcement corrosion and concrete cracking in a chloride environment. Four large concrete members were cast with horizontal reinforcements at different levels in order to create voids under the upper horizontal bars due to the well-known ‘top-bar effect.’ Then, the members were sawn into smaller specimens that included one rebar. Specimens obtained were submitted to wetting–drying cycles in salt water (natural corrosion process) until concrete cracking was observed. Results show that before concrete cracking, the corrosion pattern observed is completely different between the specimens with defect (generalised corrosion) or without defect (local pitting corrosion). The concrete cracking is delayed for specimens affected by the ‘top-bar effect’ in spite of a higher corrosion rate, and occurs at a significantly higher corrosion rate. A new model for uniform steel cross-section reduction calculation from concrete crack width in case of ‘Top-bar effect’ is proposed. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.667984

Structural response of corroded posttensioned beams / A. Castel in Journal of structural engineering, Vol. 137 N° 7 (Juillet 2011) 

Public ISBD [article]  in Journal of structural engineering > Vol. 137 N° 7 (Juillet 2011) . - pp. 761-771 Titre : Structural response of corroded posttensioned beams Type de document : texte imprimé Auteurs : A. Castel, Auteur ; D. Coronelli, Auteur ; N. A. Vu, Auteur Année de publication : 2011 Article en page(s) : pp. 761-771 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Concrete  Posttensioned  beam  Unbonded  tendons  Steel  corrosion  Finite-element  modeling Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the development of models and the analytical study of the structural response of deteriorating unbonded posttensioned beams, with the aim of providing suitable tools for the evaluation of existing deteriorated structures. The corrosion phenomena of the tendons are reviewed in the introduction. Two modeling approaches are proposed: (1) beam macro finite-elements (MFE) using cross-section analysis and (2) two-dimensional (2D) nonlinear finite-element (FE) analysis. The corrosion attack modeling considers tendon-breaking and ductility-reduction of the prestressing and mild steel. Bond deterioration is also considered for the ordinary reinforcement. The models are validated by simulating three tests on corroded beams with unbonded prestressing wires, part of the Rance benchmark exposed to 40 years of attack in a natural marine environment, and then tested for imposed loading in the laboratory. The results obtained for the global response show a good agreement with the tests at all stages of loading. The model’s predictions regarding the strain in the ordinary bars and unbonded wires are discussed in relation to the ductility reduction of the reinforcement caused by pitting corrosion and the risk of stress-corrosion cracking. Both modeling approaches are adequate, with different levels of discretization and size of the output. The MFE modeling is appealing for use in practice because of its computational simplicity. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i7/p761_s1?isAuthorized=no [article] Structural response of corroded posttensioned beams [texte imprimé] / A. Castel, Auteur ; D. Coronelli, Auteur ; N. A. Vu, Auteur . - 2011 . - pp. 761-771. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 137 N° 7 (Juillet 2011) . - pp. 761-771 Mots-clés : Concrete  Posttensioned  beam  Unbonded  tendons  Steel  corrosion  Finite-element  modeling Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : This paper presents the development of models and the analytical study of the structural response of deteriorating unbonded posttensioned beams, with the aim of providing suitable tools for the evaluation of existing deteriorated structures. The corrosion phenomena of the tendons are reviewed in the introduction. Two modeling approaches are proposed: (1) beam macro finite-elements (MFE) using cross-section analysis and (2) two-dimensional (2D) nonlinear finite-element (FE) analysis. The corrosion attack modeling considers tendon-breaking and ductility-reduction of the prestressing and mild steel. Bond deterioration is also considered for the ordinary reinforcement. The models are validated by simulating three tests on corroded beams with unbonded prestressing wires, part of the Rance benchmark exposed to 40 years of attack in a natural marine environment, and then tested for imposed loading in the laboratory. The results obtained for the global response show a good agreement with the tests at all stages of loading. The model’s predictions regarding the strain in the ordinary bars and unbonded wires are discussed in relation to the ductility reduction of the reinforcement caused by pitting corrosion and the risk of stress-corrosion cracking. Both modeling approaches are adequate, with different levels of discretization and size of the output. The MFE modeling is appealing for use in practice because of its computational simplicity. DEWEY : 624.17 ISSN : 0733-9445 En ligne : http://ascelibrary.org/sto/resource/1/jsendh/v137/i7/p761_s1?isAuthorized=no