Documents disponibles écrits par cet auteur

Prediction of concrete crack width under combined reinforcement corrosion and applied load / C. Q. Li in Journal of engineering mechanics, Vol.137 N° 11 (Novembre 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol.137 N° 11 (Novembre 2011) . - pp.722-731 Titre : Prediction of concrete crack width under combined reinforcement corrosion and applied load Type de document : texte imprimé Auteurs : C. Q. Li, Auteur ; S. T. Yang, Auteur Année de publication : 2012 Article en page(s) : pp.722-731 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Corrosion  Load  factors  Concrete  structures  Cracking  Predictions Résumé : As a global problem for reinforced concrete structures located in a chloride and/or carbon dioxide–laden environment, reinforcing steel corrosion in concrete costs approximately $100 billion per annum worldwide for maintenance and repairs. The continual demands for greater load for infrastructure exacerbate the problem. This paper attempts to examine the whole process of longitudinal cracking in concrete structures under the combined effect of reinforcement corrosion and applied load. A model for residual stiffness of cracked concrete is derived using the concept of fracture energy. It is found that the corrosion rate is the most important single factor that affects both the time-to-surface cracking and crack width growth. The paper concludes that the developed model is one of very few theoretical models that can predict with reasonable accuracy the crack width on the surface of reinforced concrete structures under such a combined effect. The developed model can be used as a tool to assess the serviceability of corrosion-affected concrete infrastructure. Timely repairs have the potential to prolong the service life of reinforced concrete structures. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i11/p722_s1?isAuthorized=no [article] Prediction of concrete crack width under combined reinforcement corrosion and applied load [texte imprimé] / C. Q. Li, Auteur ; S. T. Yang, Auteur . - 2012 . - pp.722-731. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol.137 N° 11 (Novembre 2011) . - pp.722-731 Mots-clés : Corrosion  Load  factors  Concrete  structures  Cracking  Predictions Résumé : As a global problem for reinforced concrete structures located in a chloride and/or carbon dioxide–laden environment, reinforcing steel corrosion in concrete costs approximately $100 billion per annum worldwide for maintenance and repairs. The continual demands for greater load for infrastructure exacerbate the problem. This paper attempts to examine the whole process of longitudinal cracking in concrete structures under the combined effect of reinforcement corrosion and applied load. A model for residual stiffness of cracked concrete is derived using the concept of fracture energy. It is found that the corrosion rate is the most important single factor that affects both the time-to-surface cracking and crack width growth. The paper concludes that the developed model is one of very few theoretical models that can predict with reasonable accuracy the crack width on the surface of reinforced concrete structures under such a combined effect. The developed model can be used as a tool to assess the serviceability of corrosion-affected concrete infrastructure. Timely repairs have the potential to prolong the service life of reinforced concrete structures. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i11/p722_s1?isAuthorized=no

Reinforcement corrosion initiation and activation times in concrete structures exposed to severe marine environments / R.E. Melchers in Cement and concrete research, Vol. 39 N° 11 (Novembre 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 11 (Novembre 2009) . - pp. 1068–1076 Titre : Reinforcement corrosion initiation and activation times in concrete structures exposed to severe marine environments Type de document : texte imprimé Auteurs : R.E. Melchers, Auteur ; C. Q. Li, Auteur Année de publication : 2010 Article en page(s) : pp. 1068–1076 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Corrosion;  Long-term  performance;  Chloride;  Reinforcement Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : The corrosion of steel reinforcement bars in reinforced concrete structures exposed to severe marine environments usually is attributed to the aggressive nature of chloride ions. In some cases in practice corrosion has been observed to commence already within a few years of exposure even with considerable concrete cover to the reinforcement and apparently high quality concretes. However, there are a number of other cases in practice for which corrosion initiation took much longer, even in cases with quite modest concrete cover and modest concrete quality. Many of these structures show satisfactory long-term structural performance, despite having high levels of localized chloride concentrations at the reinforcement. This disparity was noted already more than 50 years ago, but appears still not fully explained. This paper presents a systematic overview of cases reported in the engineering and corrosion literature and considers possible reasons for these differences. Consistent with observations by others, the data show that concretes made from blast furnace cements have better corrosion durability properties. The data also strongly suggest that concretes made with limestone or non-reactive dolomite aggregates or sufficiently high levels of other forms of calcium carbonates have favourable reinforcement corrosion properties. Both corrosion initiation and the onset of significant damage are delayed. Some possible reasons for this are explored briefly. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S000888460900163X [article] Reinforcement corrosion initiation and activation times in concrete structures exposed to severe marine environments [texte imprimé] / R.E. Melchers, Auteur ; C. Q. Li, Auteur . - 2010 . - pp. 1068–1076. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 11 (Novembre 2009) . - pp. 1068–1076 Mots-clés : Corrosion;  Long-term  performance;  Chloride;  Reinforcement Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : The corrosion of steel reinforcement bars in reinforced concrete structures exposed to severe marine environments usually is attributed to the aggressive nature of chloride ions. In some cases in practice corrosion has been observed to commence already within a few years of exposure even with considerable concrete cover to the reinforcement and apparently high quality concretes. However, there are a number of other cases in practice for which corrosion initiation took much longer, even in cases with quite modest concrete cover and modest concrete quality. Many of these structures show satisfactory long-term structural performance, despite having high levels of localized chloride concentrations at the reinforcement. This disparity was noted already more than 50 years ago, but appears still not fully explained. This paper presents a systematic overview of cases reported in the engineering and corrosion literature and considers possible reasons for these differences. Consistent with observations by others, the data show that concretes made from blast furnace cements have better corrosion durability properties. The data also strongly suggest that concretes made with limestone or non-reactive dolomite aggregates or sufficiently high levels of other forms of calcium carbonates have favourable reinforcement corrosion properties. Both corrosion initiation and the onset of significant damage are delayed. Some possible reasons for this are explored briefly. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S000888460900163X