Documents disponibles écrits par cet auteur

Influence of alkali, silicate, and sulfate content of carbonated concrete pore solution on mild steel corrosion behavior / B. Huet in Materials and corrosion, Vol. 61 N° 2 (Fevrier 2010) 

Public ISBD [article]  in Materials and corrosion > Vol. 61 N° 2 (Fevrier 2010) . - pp. 111–124 Titre : Influence of alkali, silicate, and sulfate content of carbonated concrete pore solution on mild steel corrosion behavior Type de document : texte imprimé Auteurs : B. Huet, Auteur ; V. L'Hostis, Auteur ; L. Tricheux, Auteur Année de publication : 2010 Article en page(s) : pp. 111–124 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Alkali;  carbonate;  cement;  mild  steel;  silicate;  sulfate Résumé : The increase in the rebar corrosion rate due to the concrete carbonation is the major cause of reinforced concrete degradation. The aim of this study was to investigate the corrosion behavior of mild steel rebars in simulated carbonated concrete solution. For this purpose, thermodynamic calculations, electrochemical techniques, gravimetric measurements, and surface analyses were used. Thermodynamic investigations of the nature of the interstitial solution provides an estimation of the influence of sulfate (equation image) and alkali (Na+, K+) content on carbonate alkalinity of the CO2/H2O open system (pCO2  = 0.3 mbar). In this system, calcium-silicate hydrates (C–S–H) remain thermodynamically unstable and amorphous silica controls silicate aqueous content at 100 ppm. Electrochemical results highlight a decrease in the corrosion rate with increasing carbonate alkalinity and the introduction of silicate. The introduction of sulfate at fixed carbonate alkalinity shows a dual effect: at high carbonate alkalinity, the corrosion rate is increased whereas at low carbonate alkalinity, corrosion rate is decreased. Those results are supported by surface analysis. Authors conclude that silicate and sulfate release from cement hydrates and fixation of alkali on carbonated hydrates are key parameters to estimate mild steel corrosion in carbonated concrete. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905244/abstract [article] Influence of alkali, silicate, and sulfate content of carbonated concrete pore solution on mild steel corrosion behavior [texte imprimé] / B. Huet, Auteur ; V. L'Hostis, Auteur ; L. Tricheux, Auteur . - 2010 . - pp. 111–124. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 61 N° 2 (Fevrier 2010) . - pp. 111–124 Mots-clés : Alkali;  carbonate;  cement;  mild  steel;  silicate;  sulfate Résumé : The increase in the rebar corrosion rate due to the concrete carbonation is the major cause of reinforced concrete degradation. The aim of this study was to investigate the corrosion behavior of mild steel rebars in simulated carbonated concrete solution. For this purpose, thermodynamic calculations, electrochemical techniques, gravimetric measurements, and surface analyses were used. Thermodynamic investigations of the nature of the interstitial solution provides an estimation of the influence of sulfate (equation image) and alkali (Na+, K+) content on carbonate alkalinity of the CO2/H2O open system (pCO2  = 0.3 mbar). In this system, calcium-silicate hydrates (C–S–H) remain thermodynamically unstable and amorphous silica controls silicate aqueous content at 100 ppm. Electrochemical results highlight a decrease in the corrosion rate with increasing carbonate alkalinity and the introduction of silicate. The introduction of sulfate at fixed carbonate alkalinity shows a dual effect: at high carbonate alkalinity, the corrosion rate is increased whereas at low carbonate alkalinity, corrosion rate is decreased. Those results are supported by surface analysis. Authors conclude that silicate and sulfate release from cement hydrates and fixation of alkali on carbonated hydrates are key parameters to estimate mild steel corrosion in carbonated concrete. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905244/abstract

Modelling the corrosion-induced cracking of reinforced concrete structures exposed to the atmosphere / V. L'Hostis in Materials and corrosion, Vol. 62 N° 10 (Octobre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 10 (Octobre 2011) . - pp. 943–947 Titre : Modelling the corrosion-induced cracking of reinforced concrete structures exposed to the atmosphere Type de document : texte imprimé Auteurs : V. L'Hostis, Auteur ; A. Millard, Auteur ; S. Perrin, Auteur Année de publication : 2012 Article en page(s) : pp. 943–947 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Atmospheric  corrosion  Cementitious  materials  Modelling  Oxygen  reduction Résumé : The prediction of concrete cracking due to corrosion in atmospheric/carbonated conditions is a major issue for the evaluation of the durability of structures and the choice of maintenance policies. Because of the complexity of the phenomenon, a fully predictive approach is still missing. The proposed work can be considered as one step in this direction. It deals with a modelling study achieved at the Commissariat à l'Energie Atomique (CEA) with the CAST3M finite elements software. Model is constituted of three components: (1) concrete hydric behaviour, (2) rebar corrosion and (3) mechanical consequences on concrete (mainly concrete cracking). Actual developments consider analogies between rebar corrosion mechanisms and atmospheric corrosion ones, assuming that corrosion processes are influenced by the relative humidity evolution of atmosphere and/or of concrete. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905578/abstract [article] Modelling the corrosion-induced cracking of reinforced concrete structures exposed to the atmosphere [texte imprimé] / V. L'Hostis, Auteur ; A. Millard, Auteur ; S. Perrin, Auteur . - 2012 . - pp. 943–947. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 10 (Octobre 2011) . - pp. 943–947 Mots-clés : Atmospheric  corrosion  Cementitious  materials  Modelling  Oxygen  reduction Résumé : The prediction of concrete cracking due to corrosion in atmospheric/carbonated conditions is a major issue for the evaluation of the durability of structures and the choice of maintenance policies. Because of the complexity of the phenomenon, a fully predictive approach is still missing. The proposed work can be considered as one step in this direction. It deals with a modelling study achieved at the Commissariat à l'Energie Atomique (CEA) with the CAST3M finite elements software. Model is constituted of three components: (1) concrete hydric behaviour, (2) rebar corrosion and (3) mechanical consequences on concrete (mainly concrete cracking). Actual developments consider analogies between rebar corrosion mechanisms and atmospheric corrosion ones, assuming that corrosion processes are influenced by the relative humidity evolution of atmosphere and/or of concrete. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905578/abstract

Study of the active/passive corrosion behaviour of reinforced concrete slabs using different devices / V. L'Hostis 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. 481-490 Titre : Study of the active/passive corrosion behaviour of reinforced concrete slabs using different devices Type de document : texte imprimé Auteurs : V. L'Hostis, Auteur ; E. Marie-Victoire, Auteur ; V. Bouteiller, Auteur Année de publication : 2012 Article en page(s) : pp. 481-490 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Reinforced  concrete  corrosion  Electrochemical  measurements  Chlorides  Carbonation Résumé : This paper deals with results of electrochemical measurements carried out on reinforced concrete slabs. Measurements were performed four times a year over a period of two years by means of three kinds of device: a Gamry© laboratory potentiostat, and Gecor6© and Galvapulse© on-site apparatuses. Results showed that all devices are able to detect passive corrosion. They coherently diagnose chloride-containing-slabs and can detect the depassivation of rebars. The variability of the depassivation time was pointed out as far as chloride-induced-corrosion is concerned. Conversely, corrosion levels proposed by the three devices are different in the case of carbonation (generalised)-induced corrosion, even if all of them detect the active corrosion state. This discrepancy showed that the use of these results in term of steel loss is not possible. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668010 [article] Study of the active/passive corrosion behaviour of reinforced concrete slabs using different devices [texte imprimé] / V. L'Hostis, Auteur ; E. Marie-Victoire, Auteur ; V. Bouteiller, Auteur . - 2012 . - pp. 481-490. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 3-4 (Mars/Avril 2012) . - pp. 481-490 Mots-clés : Reinforced  concrete  corrosion  Electrochemical  measurements  Chlorides  Carbonation Résumé : This paper deals with results of electrochemical measurements carried out on reinforced concrete slabs. Measurements were performed four times a year over a period of two years by means of three kinds of device: a Gamry© laboratory potentiostat, and Gecor6© and Galvapulse© on-site apparatuses. Results showed that all devices are able to detect passive corrosion. They coherently diagnose chloride-containing-slabs and can detect the depassivation of rebars. The variability of the depassivation time was pointed out as far as chloride-induced-corrosion is concerned. Conversely, corrosion levels proposed by the three devices are different in the case of carbonation (generalised)-induced corrosion, even if all of them detect the active corrosion state. This discrepancy showed that the use of these results in term of steel loss is not possible. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668010