Documents disponibles écrits par cet auteur

Changes in C3S hydration in the presence of cellulose ethers / J. Pourchez in Cement and concrete research, Vol. 40 N° 2 (02 ex.) (Fevrier 2010) 

Public ISBD [article]  in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 179-188 Titre : Changes in C3S hydration in the presence of cellulose ethers Type de document : texte imprimé Auteurs : J. Pourchez, Auteur ; P. Grosseau, Auteur ; B. Ruot, Auteur Année de publication : 2010 Article en page(s) : pp. 179-188 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cellulose  ethers  Hydration  Adsorption  Dissolution  Nucleation Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : The influence of cellulose ethers (CE) on C3S hydration processes was examined in order to improve our knowledge of the retarding effect of cellulose ethers on the cement hydration kinetics. In this frame, the impacts of various cellulose ethers on C3S dissolution, C-S-H nucleation-growth process and portlandite precipitation were investigated. A weak influence of cellulose ethers on the dissolution kinetics of pure C3S phase was observed. In contrast, a significant decrease of the initial amount of C-S-H nuclei and a strong modification of the growth rate of C-S-H were noticed. A slowing down of the portlandite precipitation was also demonstrated in the case of both cement and C3S hydration. CE adsorption behavior clearly highlighted a chemical structure dependence as well as a cement phase dependence. Finally, we supported the conclusion that CE adsorption is doubtless responsible for the various retarding effect observed as a function of CE types. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XK31Y3-2&_user=6 [...] [article] Changes in C3S hydration in the presence of cellulose ethers [texte imprimé] / J. Pourchez, Auteur ; P. Grosseau, Auteur ; B. Ruot, Auteur . - 2010 . - pp. 179-188. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 179-188 Mots-clés : Cellulose  ethers  Hydration  Adsorption  Dissolution  Nucleation Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : The influence of cellulose ethers (CE) on C3S hydration processes was examined in order to improve our knowledge of the retarding effect of cellulose ethers on the cement hydration kinetics. In this frame, the impacts of various cellulose ethers on C3S dissolution, C-S-H nucleation-growth process and portlandite precipitation were investigated. A weak influence of cellulose ethers on the dissolution kinetics of pure C3S phase was observed. In contrast, a significant decrease of the initial amount of C-S-H nuclei and a strong modification of the growth rate of C-S-H were noticed. A slowing down of the portlandite precipitation was also demonstrated in the case of both cement and C3S hydration. CE adsorption behavior clearly highlighted a chemical structure dependence as well as a cement phase dependence. Finally, we supported the conclusion that CE adsorption is doubtless responsible for the various retarding effect observed as a function of CE types. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XK31Y3-2&_user=6 [...]

Current understanding of cellulose ethers impact on the hydration of C3A and C3A-sulphate systems / J. Pourchez in Cement and concrete research, Vol. 39 N° 8 (Août 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 8 (Août 2009) . - pp. 664–669 Titre : Current understanding of cellulose ethers impact on the hydration of C3A and C3A-sulphate systems Type de document : texte imprimé Auteurs : J. Pourchez, Auteur ; P. Grosseau, Auteur ; B. Ruot, Auteur Année de publication : 2009 Article en page(s) : pp. 664–669 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cellulose  ethers;  Hydration;  Adsorption;  C3A;  Calcium  sulphate Résumé : The impact of cellulose ethers (CE) on C3A hydration was examined to support the understanding of the retarding effect of CE on cement hydration. In this sense, we successively studied the CE adsorption on ettringite and calcium hydroaluminates, and then the CE influence during C3A hydration in presence or absence of calcium sulphate. We emphasized a phase-specific adsorption of CE depending on CE chemistry. Besides, in addition of CE, we highlighted a gradual slowing down of C3A dissolution as well as ettringite and calcium hydroaluminates precipitation. Again, a great impact of CE chemistry and CE adsorption behaviour were noticed. Thus, HECs induce always a stronger adsorption on calcium hydroaluminates and a longer C3A hydration delays than HPMCs. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001239 [article] Current understanding of cellulose ethers impact on the hydration of C3A and C3A-sulphate systems [texte imprimé] / J. Pourchez, Auteur ; P. Grosseau, Auteur ; B. Ruot, Auteur . - 2009 . - pp. 664–669. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 8 (Août 2009) . - pp. 664–669 Mots-clés : Cellulose  ethers;  Hydration;  Adsorption;  C3A;  Calcium  sulphate Résumé : The impact of cellulose ethers (CE) on C3A hydration was examined to support the understanding of the retarding effect of CE on cement hydration. In this sense, we successively studied the CE adsorption on ettringite and calcium hydroaluminates, and then the CE influence during C3A hydration in presence or absence of calcium sulphate. We emphasized a phase-specific adsorption of CE depending on CE chemistry. Besides, in addition of CE, we highlighted a gradual slowing down of C3A dissolution as well as ettringite and calcium hydroaluminates precipitation. Again, a great impact of CE chemistry and CE adsorption behaviour were noticed. Thus, HECs induce always a stronger adsorption on calcium hydroaluminates and a longer C3A hydration delays than HPMCs. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001239

Some aspects of cellulose ethers influence on water transport and porous structure of cement-based materials / J. Pourchez in Cement and concrete research, Vol. 40 N° 2 (02 ex.) (Fevrier 2010) 

Public ISBD [article]  in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 242-252 Titre : Some aspects of cellulose ethers influence on water transport and porous structure of cement-based materials Type de document : texte imprimé Auteurs : J. Pourchez, Auteur ; B. Ruot, Auteur ; J. Debayle, Auteur Année de publication : 2010 Article en page(s) : pp. 242-252 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cellulose  ethers  Porous  structure  Water  transport  Microtomography Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : This paper evaluates and compares the impact of cellulose ethers (CE) on water transport and porous structure of cement-based materials in both fresh and hardened state. Investigations of the porous network (mercury intrusion porosimetry, apparent density, 2D and 3D observations) emphasize an air-entrained stabilisation depending on CE chemistry. We also highlight that CE chemistry leads to a gradual effect on characteristics of the water transport. The global tendencies brought by CE are: higher water retention, lower capillarity water absorption, lower liquid water permeability as well as higher water vapour permeability. All things considered, we demonstrate that CE chemistry is an important controlling factor on water transport and porous structure evolution. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XJN4W8-2&_user=6 [...] [article] Some aspects of cellulose ethers influence on water transport and porous structure of cement-based materials [texte imprimé] / J. Pourchez, Auteur ; B. Ruot, Auteur ; J. Debayle, Auteur . - 2010 . - pp. 242-252. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 242-252 Mots-clés : Cellulose  ethers  Porous  structure  Water  transport  Microtomography Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : This paper evaluates and compares the impact of cellulose ethers (CE) on water transport and porous structure of cement-based materials in both fresh and hardened state. Investigations of the porous network (mercury intrusion porosimetry, apparent density, 2D and 3D observations) emphasize an air-entrained stabilisation depending on CE chemistry. We also highlight that CE chemistry leads to a gradual effect on characteristics of the water transport. The global tendencies brought by CE are: higher water retention, lower capillarity water absorption, lower liquid water permeability as well as higher water vapour permeability. All things considered, we demonstrate that CE chemistry is an important controlling factor on water transport and porous structure evolution. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XJN4W8-2&_user=6 [...]