Documents disponibles écrits par cet auteur

Rheology of fiber reinforced cementitious materials / Laetitia Martinie 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. 226-234 Titre : Rheology of fiber reinforced cementitious materials : classification and prediction Type de document : texte imprimé Auteurs : Laetitia Martinie, Auteur ; Pierre Rossi, Auteur ; Nicolas Roussel, Auteur Année de publication : 2010 Article en page(s) : pp. 226-234 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Rheology  Mixture  proportioning  Fresh  concrete  Aggregate  Fiber  reinforcement Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : In this paper, the effect of rigid straight fibers on the yield stress of cementitious materials is studied. A simple model describing the contact network between rigid fibers inside the material is first derived from the physical phenomena involved in the case of spherical inclusions. As soon as this contact network becomes percolated, the yield stress of the mixture increases by several orders of magnitude. A prediction of the critical fiber amount leading to a very strong increase of the yield stress of any cement paste, mortar or concrete is then derived. A simple and helpful mix design criterion for Ultra High Performance Fiber Reinforced Concretes is finally proposed and applied to several mix proportions from literature. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XDKCDW-1&_user=6 [...] [article] Rheology of fiber reinforced cementitious materials : classification and prediction [texte imprimé] / Laetitia Martinie, Auteur ; Pierre Rossi, Auteur ; Nicolas Roussel, Auteur . - 2010 . - pp. 226-234. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 226-234 Mots-clés : Rheology  Mixture  proportioning  Fresh  concrete  Aggregate  Fiber  reinforcement Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : In this paper, the effect of rigid straight fibers on the yield stress of cementitious materials is studied. A simple model describing the contact network between rigid fibers inside the material is first derived from the physical phenomena involved in the case of spherical inclusions. As soon as this contact network becomes percolated, the yield stress of the mixture increases by several orders of magnitude. A prediction of the critical fiber amount leading to a very strong increase of the yield stress of any cement paste, mortar or concrete is then derived. A simple and helpful mix design criterion for Ultra High Performance Fiber Reinforced Concretes is finally proposed and applied to several mix proportions from literature. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XDKCDW-1&_user=6 [...]

Steady state flow of cement suspensions / Nicolas Roussel in Cement and concrete research, Vol. 40 N° 1 (Janvier 2010) 

Public ISBD [article]  in Cement and concrete research > Vol. 40 N° 1 (Janvier 2010) . - pp. 77-84 Titre : Steady state flow of cement suspensions : a micromechanical state of the art Type de document : texte imprimé Auteurs : Nicolas Roussel, Auteur ; Anael Lemaître, Auteur ; Robert J. Flatt, Auteur Article en page(s) : pp. 77-84 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Admixture  Particles  Rheology  Shear  thickening  Yield  stress Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : Fresh cementitious pastes can be viewed as suspensions of particles of many different sizes (from several tens of nm to 100 μm) in a continuous fluid phase. This broad poly-dispersity implies that various interactions such as surface forces (or colloidal interactions), Brownian forces, hydrodynamic forces or various contact forces between particles interplay. Depending on the volume fraction of the particles in the mixture, the use of admixtures or the magnitude of either the applied stress or strain rate, one or several of these interactions dominate. Our objective here is not to quantitatively predict rheology of cement pastes but rather to understand and classify the situations where, depending on composition and processing, one or other of the physical phenomena will control the macroscopic behavior. The result of this analysis is a conceptual diagram of predominant interactions in flowing cementitious suspensions under simple shear, as a function of shear rate and solid fraction. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235562%23 [...] [article] Steady state flow of cement suspensions : a micromechanical state of the art [texte imprimé] / Nicolas Roussel, Auteur ; Anael Lemaître, Auteur ; Robert J. Flatt, Auteur . - pp. 77-84. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 1 (Janvier 2010) . - pp. 77-84 Mots-clés : Admixture  Particles  Rheology  Shear  thickening  Yield  stress Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : Fresh cementitious pastes can be viewed as suspensions of particles of many different sizes (from several tens of nm to 100 μm) in a continuous fluid phase. This broad poly-dispersity implies that various interactions such as surface forces (or colloidal interactions), Brownian forces, hydrodynamic forces or various contact forces between particles interplay. Depending on the volume fraction of the particles in the mixture, the use of admixtures or the magnitude of either the applied stress or strain rate, one or several of these interactions dominate. Our objective here is not to quantitatively predict rheology of cement pastes but rather to understand and classify the situations where, depending on composition and processing, one or other of the physical phenomena will control the macroscopic behavior. The result of this analysis is a conceptual diagram of predominant interactions in flowing cementitious suspensions under simple shear, as a function of shear rate and solid fraction. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235562%23 [...]