Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process / Angliang Zhang in Cement and concrete research, Vol. 40 N° 3 (Mars 2010)  

Public ISBD [article]  inCement and concrete research > Vol. 40 N° 3 (Mars 2010) . - pp. 415–425 Titre : Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process Type de document : texte imprimé Auteurs : Angliang Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 415–425 Note générale : Bibliogr. Langues : Anglais (eng) Mots-clés : Crack detection  Corrosion Reinforcement Concrete Modeling Résumé : This paper deals with the evolution of the corrosion pattern based on two beams corroded by 14 years (beam B1CL1) and 23 years (beam B2CL1) of conservation in a chloride environment. The experimental results indicate that, at the cracking initiation stage and the first stage of cracking propagation, localized corrosion due to chloride ingress is the predominant corrosion pattern and pitting corrosion is the main factor that influences the cracking process. As corrosion cracking increases, general corrosion develops rapidly and gradually becomes predominant in the second stage of cracking propagation. A comparison between existing models and experimental results illustrates that, although Vidal et al.'s model can better predict the reinforcement corrosion of beam B1CL1 under localized corrosion, it cannot predict the corrosion of beam B2CL1 under general corrosion. Also, Rodriguez's model, derived from the general corrosion due to electrically accelerated corrosion experiments, cannot match natural chloride corrosion irrespective of whether corrosion is localized or general. Thus, for natural general corrosion in the second stage of cracking propagation, a new model based on the parameter of average steel cross-section loss is put forward to predict steel corrosion from corrosion cracking. En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609002798 [article] Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process [texte imprimé] / Angliang Zhang, Auteur . - 2012 . - pp. 415–425. Bibliogr. Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 3 (Mars 2010) . - pp. 415–425 Mots-clés : Crack detection  Corrosion Reinforcement Concrete Modeling Résumé : This paper deals with the evolution of the corrosion pattern based on two beams corroded by 14 years (beam B1CL1) and 23 years (beam B2CL1) of conservation in a chloride environment. The experimental results indicate that, at the cracking initiation stage and the first stage of cracking propagation, localized corrosion due to chloride ingress is the predominant corrosion pattern and pitting corrosion is the main factor that influences the cracking process. As corrosion cracking increases, general corrosion develops rapidly and gradually becomes predominant in the second stage of cracking propagation. A comparison between existing models and experimental results illustrates that, although Vidal et al.'s model can better predict the reinforcement corrosion of beam B1CL1 under localized corrosion, it cannot predict the corrosion of beam B2CL1 under general corrosion. Also, Rodriguez's model, derived from the general corrosion due to electrically accelerated corrosion experiments, cannot match natural chloride corrosion irrespective of whether corrosion is localized or general. Thus, for natural general corrosion in the second stage of cracking propagation, a new model based on the parameter of average steel cross-section loss is put forward to predict steel corrosion from corrosion cracking. En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609002798

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Y - Al2O3 modified with praseodymium / Zhiqiao He in Industrial & engineering chemistry research, Vol. 49 N° 24 (Décembre 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12345–12351 Titre : Y - Al2O3 modified with praseodymium : an application in the heterogeneous catalytic ozonation of succinic acid in aqueous solution Type de document : texte imprimé Auteurs : Zhiqiao He, Auteur ; Angliang Zhang, Auteur ; Shuang Song, Auteur Année de publication : 2011 Article en page(s) : pp.12345–12351 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic ozonation Succinic acid Aqueous solution Résumé : In an attempt to utilize ozone effectively, a series of praseodymium-modified γ-Al2O3 (Pr/Al2O3) was prepared via incipient wetness impregnation using Pr(NO3)3·6H2O as the precursor. The structure and properties of the catalysts were studied by X-ray diffraction (XRD) and the Brunauer−Emmett−Teller (BET) method. Catalytic activity was evaluated by monitoring the degradation of succinic acid (SA) in the presence of ozone. The praseodymium modification can effectively enhance the ozonation activity of γ-Al2O3 upon SA removal. Increasing the calcination temperature of Pr/Al2O3 is disadvantageous for the catalytic process, whereas increasing the load of praseodymium is helpful. After three successive cycles, the Pr/Al2O3 catalyst remained stable in the catalytic ozonation of SA. Overall, the initial degradation rate of SA, as well as the saturated adsorption capacity of SA, were found to have a linear relation to changes of the surface hydroxyl groups of the catalyst. On this basis, we conclude that the significant enhancement of SA degradation using Pr/Al2O3 as a catalyst should be because praseodymium, in the form of Pr6O11, promoted the formation of surface hydroxyl groups. Hence, the adsorption was increased, and the degradation rate of SA was enhanced. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101233h [article] Y - Al2O3 modified with praseodymium : an application in the heterogeneous catalytic ozonation of succinic acid in aqueous solution [texte imprimé] / Zhiqiao He, Auteur ; Angliang Zhang, Auteur ; Shuang Song, Auteur . - 2011 . - pp.12345–12351. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12345–12351 Mots-clés : Catalytic ozonation Succinic acid Aqueous solution Résumé : In an attempt to utilize ozone effectively, a series of praseodymium-modified γ-Al2O3 (Pr/Al2O3) was prepared via incipient wetness impregnation using Pr(NO3)3·6H2O as the precursor. The structure and properties of the catalysts were studied by X-ray diffraction (XRD) and the Brunauer−Emmett−Teller (BET) method. Catalytic activity was evaluated by monitoring the degradation of succinic acid (SA) in the presence of ozone. The praseodymium modification can effectively enhance the ozonation activity of γ-Al2O3 upon SA removal. Increasing the calcination temperature of Pr/Al2O3 is disadvantageous for the catalytic process, whereas increasing the load of praseodymium is helpful. After three successive cycles, the Pr/Al2O3 catalyst remained stable in the catalytic ozonation of SA. Overall, the initial degradation rate of SA, as well as the saturated adsorption capacity of SA, were found to have a linear relation to changes of the surface hydroxyl groups of the catalyst. On this basis, we conclude that the significant enhancement of SA degradation using Pr/Al2O3 as a catalyst should be because praseodymium, in the form of Pr6O11, promoted the formation of surface hydroxyl groups. Hence, the adsorption was increased, and the degradation rate of SA was enhanced. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101233h

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire