Documents disponibles écrits par cet auteur

Monitoring of corrosion processes in chloride contaminated mortar by electrochemical measurements and X-ray tomography / M. Beck in Materials and corrosion, Vol. 61 N° 6 (Juin 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 6 (Juin 2010) . - pp. 475–479 Titre : Monitoring of corrosion processes in chloride contaminated mortar by electrochemical measurements and X-ray tomography Type de document : texte imprimé Auteurs : M. Beck, Auteur ; J. Goebbels, Auteur ; A. Burkert, Auteur Année de publication : 2010 Article en page(s) : pp. 475–479 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : contaminated  mortar;  electrochemical  measurements;  pitting  corrosion;  X-ray  tomography Résumé : Corrosion of steel reinforcement in concrete exposed to chloride containing environments is a serious problem in civil engineering practice. Electrochemical methods, e.g., potential mapping, provide information whether the steel reinforcement is still passive or depassivation has been initiated. By applying such techniques no information on the type of corrosion, its extent and distribution of corrosion products is available. Particular the corrosion progress is a significant problem. Especially in the case of macrocell corrosion in reinforced concrete structures, the development at the anode cannot be separated into corrosion damage resulting from macrocell corrosion or self-corrosion. Until now also in laboratory tests it is impossible to collect such information without destroying specimens after electrochemical testing was performed. To overcome this problem it was tried to study the steel surface within the mortar specimens by X-ray tomography (CT). Within the scope of these investigations it could be shown, that X-ray tomography is suitable to make corrosion pits and their development visible which are embedded in a mortar with a cover thickness of about 35 mm. In this publication the time-dependent corrosion damage of reinforced steel is documented by X-ray tomography. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905364/abstract [article] Monitoring of corrosion processes in chloride contaminated mortar by electrochemical measurements and X-ray tomography [texte imprimé] / M. Beck, Auteur ; J. Goebbels, Auteur ; A. Burkert, Auteur . - 2010 . - pp. 475–479. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 6 (Juin 2010) . - pp. 475–479 Mots-clés : contaminated  mortar;  electrochemical  measurements;  pitting  corrosion;  X-ray  tomography Résumé : Corrosion of steel reinforcement in concrete exposed to chloride containing environments is a serious problem in civil engineering practice. Electrochemical methods, e.g., potential mapping, provide information whether the steel reinforcement is still passive or depassivation has been initiated. By applying such techniques no information on the type of corrosion, its extent and distribution of corrosion products is available. Particular the corrosion progress is a significant problem. Especially in the case of macrocell corrosion in reinforced concrete structures, the development at the anode cannot be separated into corrosion damage resulting from macrocell corrosion or self-corrosion. Until now also in laboratory tests it is impossible to collect such information without destroying specimens after electrochemical testing was performed. To overcome this problem it was tried to study the steel surface within the mortar specimens by X-ray tomography (CT). Within the scope of these investigations it could be shown, that X-ray tomography is suitable to make corrosion pits and their development visible which are embedded in a mortar with a cover thickness of about 35 mm. In this publication the time-dependent corrosion damage of reinforced steel is documented by X-ray tomography. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905364/abstract

Morphology of corrosion products of steel in concrete under macro-cell and self-corrosion conditions / D. Neff in Materials and corrosion, Vol. 62 N° 9 (Septembre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 861–871 Titre : Morphology of corrosion products of steel in concrete under macro-cell and self-corrosion conditions Type de document : texte imprimé Auteurs : D. Neff, Auteur ; J. Harnisch, Auteur ; M. Beck, Auteur Année de publication : 2011 Article en page(s) : pp. 861–871 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Corrosion  Concrete  Chlorides  Iron  hydroxychloride  X-ray  tomography  Raman  spectroscopy Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper investigations into the formation of specific corrosion products during the process of chloride induced corrosion of steel in concrete are presented. The extension of corrosion products within concrete was established by means of X-ray tomography analyses. Then a detailed analysis of the nature of corrosion products has been conducted by means of Raman micro-spectroscopy and energy dispersive spectroscopy. Results emphasize two different corrosion patterns. The first one is composed of shallow cavities, where mostly magnetite and goethite were identified, traducing aerated to moderate aerated conditions in these media. The second pattern was identified as deep, needle-like pits, where chlorinated-iron-oxides phases were present associated with more or less important chloride enrichments. The presence of these particular species is indicating low redox and low pH conditions within these pits. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005861/abstract [article] Morphology of corrosion products of steel in concrete under macro-cell and self-corrosion conditions [texte imprimé] / D. Neff, Auteur ; J. Harnisch, Auteur ; M. Beck, Auteur . - 2011 . - pp. 861–871. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 9 (Septembre 2011) . - pp. 861–871 Mots-clés : Corrosion  Concrete  Chlorides  Iron  hydroxychloride  X-ray  tomography  Raman  spectroscopy Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper investigations into the formation of specific corrosion products during the process of chloride induced corrosion of steel in concrete are presented. The extension of corrosion products within concrete was established by means of X-ray tomography analyses. Then a detailed analysis of the nature of corrosion products has been conducted by means of Raman micro-spectroscopy and energy dispersive spectroscopy. Results emphasize two different corrosion patterns. The first one is composed of shallow cavities, where mostly magnetite and goethite were identified, traducing aerated to moderate aerated conditions in these media. The second pattern was identified as deep, needle-like pits, where chlorinated-iron-oxides phases were present associated with more or less important chloride enrichments. The presence of these particular species is indicating low redox and low pH conditions within these pits. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005861/abstract