About microcracking due to leaching in cementitious composites / Thomas Rougelot in Cement and concrete research, Vol. 40 N° 2 (02 ex.) (Fevrier 2010)  

Public ISBD [article]  inCement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 271-283 Titre : About microcracking due to leaching in cementitious composites : x-ray microtomography description and numerical approach Type de document : texte imprimé Auteurs : Thomas Rougelot, Auteur ; Nicolas Burlion, Auteur ; Dominique Bernard, Auteur Année de publication : 2010 Article en page(s) : pp. 271-283 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cementitious composites Endogenous and decalcification shrinkages Leaching Microcracking X-ray computed microtomography Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : Chemical shock of cement based materials leads to significant degradation of their physical properties. A typical scenario is a calcium leaching due to water (water with very low pH compared with that of pore fluid). The main objective of this paper is to evaluate the evolution of microstructure induced by leaching of a cementitious composite using synchrotron X-ray micro tomography, mainly from an experimental point of view. In this particular case, it was possible to identify cracking induced by leaching. After a description of the degradation mechanism and the X-ray synchrotron microtomographic analysis, numerical simulations are performed in order to show that cracking is induced by an initial pre-stressing of the composite, coupled with decalcification shrinkage and dramatic decrease in tensile strength during leaching. X-ray microtomography analysis allowed to make evidence of an induced microcracking in cementitious material submitted to leaching. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XHT4G5-2&_user=6 [...] [article] About microcracking due to leaching in cementitious composites : x-ray microtomography description and numerical approach [texte imprimé] / Thomas Rougelot, Auteur ; Nicolas Burlion, Auteur ; Dominique Bernard, Auteur . - 2010 . - pp. 271-283. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 271-283 Mots-clés : Cementitious composites Endogenous and decalcification shrinkages Leaching Microcracking X-ray computed microtomography Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : Chemical shock of cement based materials leads to significant degradation of their physical properties. A typical scenario is a calcium leaching due to water (water with very low pH compared with that of pore fluid). The main objective of this paper is to evaluate the evolution of microstructure induced by leaching of a cementitious composite using synchrotron X-ray micro tomography, mainly from an experimental point of view. In this particular case, it was possible to identify cracking induced by leaching. After a description of the degradation mechanism and the X-ray synchrotron microtomographic analysis, numerical simulations are performed in order to show that cracking is induced by an initial pre-stressing of the composite, coupled with decalcification shrinkage and dramatic decrease in tensile strength during leaching. X-ray microtomography analysis allowed to make evidence of an induced microcracking in cementitious material submitted to leaching. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XHT4G5-2&_user=6 [...]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Porosity of concrete / Fan Zhang in European journal of environmental and civil engineering, Vol. 16 N° 3-4 (Mars/Avril 2012)  

Public ISBD [article]  inEuropean journal of environmental and civil engineering > Vol. 16 N° 3-4 (Mars/Avril 2012) . - pp. 311-321 Titre : Porosity of concrete : Influence of test conditions and material variability Type de document : texte imprimé Auteurs : Fan Zhang, Auteur ; Thomas Rougelot, Auteur ; Nicolas Burlion, Auteur Année de publication : 2012 Article en page(s) : pp. 311-321 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Variability Spatial variability Concrete Porosity Experimental biases Résumé : The prediction of the service lifetime of civil engineering structures needs an appropriate comprehension and quantification of the physical, chemical and mechanical processes associated with the durability of structural reinforced concrete. In particular, the porosity is an essential property involved in degradation of concretes. Also, the development of a probabilistic approach could enhance estimations of service lifetime. Experimental tests are therefore performed in the framework of project APPLET and aim at quantifying variabilities linked to concrete itself and its setting in a real structure. A spatial variability and the effect of the drying protocol for the measurement of porosity have been highlighted. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.667709 [article] Porosity of concrete : Influence of test conditions and material variability [texte imprimé] / Fan Zhang, Auteur ; Thomas Rougelot, Auteur ; Nicolas Burlion, Auteur . - 2012 . - pp. 311-321. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 3-4 (Mars/Avril 2012) . - pp. 311-321 Mots-clés : Variability Spatial variability Concrete Porosity Experimental biases Résumé : The prediction of the service lifetime of civil engineering structures needs an appropriate comprehension and quantification of the physical, chemical and mechanical processes associated with the durability of structural reinforced concrete. In particular, the porosity is an essential property involved in degradation of concretes. Also, the development of a probabilistic approach could enhance estimations of service lifetime. Experimental tests are therefore performed in the framework of project APPLET and aim at quantifying variabilities linked to concrete itself and its setting in a real structure. A spatial variability and the effect of the drying protocol for the measurement of porosity have been highlighted. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.667709

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Water desorption and shrinkage in mortars and cement pastes: Experimental study and poromechanical model / Thomas Rougelota in Cement and concrete research, Vol. 39 N° 1 (Janvier 2009)  

Public ISBD [article]  inCement and concrete research > Vol. 39 N° 1 (Janvier 2009) . - pp. 36–44 Titre : Water desorption and shrinkage in mortars and cement pastes: Experimental study and poromechanical model Type de document : texte imprimé Auteurs : Thomas Rougelota, Auteur ; Frédéric Skoczylas, Auteur ; Nicolas Burlion, Auteur Année de publication : 2009 Article en page(s) : pp. 36–44 Langues : Anglais (eng) Mots-clés : Water desorption curves  Cement paste  Mortar  Shrinkage  Modelling Résumé : The aim of the present research was to study moisture changes and strains induced by smooth water desorption of several cement based materials. The main advantage of this small-steps drying is to dramatically limit the structural effect within tested samples, by lowering moisture gradients and therefore cracking due to differential shrinkage. Resulting data are of importance as they allow water retention curves, porosity distribution and desiccation shrinkage to be determined versus a large range of relative humidity. Experiments were conducted on ordinary mortars and cement pastes with water-to-cement ratio of 0.5 and 0.8. The role of the cementitious matrix and of aggregates over water-related behaviour of these materials can also be studied. Finally, a simple numerical model, based on experimental poromechanical results, was proposed to predict the shrinkage when the material is submitted to drying. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884608001944 [article] Water desorption and shrinkage in mortars and cement pastes: Experimental study and poromechanical model [texte imprimé] / Thomas Rougelota, Auteur ; Frédéric Skoczylas, Auteur ; Nicolas Burlion, Auteur . - 2009 . - pp. 36–44. Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 1 (Janvier 2009) . - pp. 36–44 Mots-clés : Water desorption curves  Cement paste  Mortar  Shrinkage  Modelling Résumé : The aim of the present research was to study moisture changes and strains induced by smooth water desorption of several cement based materials. The main advantage of this small-steps drying is to dramatically limit the structural effect within tested samples, by lowering moisture gradients and therefore cracking due to differential shrinkage. Resulting data are of importance as they allow water retention curves, porosity distribution and desiccation shrinkage to be determined versus a large range of relative humidity. Experiments were conducted on ordinary mortars and cement pastes with water-to-cement ratio of 0.5 and 0.8. The role of the cementitious matrix and of aggregates over water-related behaviour of these materials can also be studied. Finally, a simple numerical model, based on experimental poromechanical results, was proposed to predict the shrinkage when the material is submitted to drying. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884608001944

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Why is it necessary to use a damage model to simulate the mechanical behavior of concrete under drying and leaching? / Thomas Rougelot in European journal of environmental and civil engineering, Vol. 14 N° 6-7 (Juin 2010)  

Public ISBD [article]  inEuropean journal of environmental and civil engineering > Vol. 14 N° 6-7 (Juin 2010) . - pp. 923-935 Titre : Why is it necessary to use a damage model to simulate the mechanical behavior of concrete under drying and leaching? Type de document : texte imprimé Auteurs : Thomas Rougelot, Auteur ; Cheng Peng, Auteur ; Nicolas Burlion, Auteur Année de publication : 2011 Article en page(s) : pp. 923-935 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cementitious materials Drying Leaching Damage X-ray microtomography Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Short and long-term behaviors of concrete structures are of importance when dealing with durability aspects. One particular interesting aspect is the change in microstructure of concrete submitted to drying or leaching processes, and a potentially induced cracking pattern. Experimental investigations which focus on the effect of the dimensions of aggregates over cracks are proposed in this paper. The samples are submitted to accelerated leaching or to drying, and the evolution of their microstructure is regularly recorded by means of X-ray microtomography. A method is then proposed to study the cracking pattern, which appears to be greatly dependant of the size of inclusions. In particular, it appears that a larger diameter of inclusions tends to increase the crack opening. DEWEY : 624 ISSN : 1964-8189 En ligne : http://ejece.revuesonline.com/resnum.jsp [article] Why is it necessary to use a damage model to simulate the mechanical behavior of concrete under drying and leaching? [texte imprimé] / Thomas Rougelot, Auteur ; Cheng Peng, Auteur ; Nicolas Burlion, Auteur . - 2011 . - pp. 923-935. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 14 N° 6-7 (Juin 2010) . - pp. 923-935 Mots-clés : Cementitious materials Drying Leaching Damage X-ray microtomography Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Short and long-term behaviors of concrete structures are of importance when dealing with durability aspects. One particular interesting aspect is the change in microstructure of concrete submitted to drying or leaching processes, and a potentially induced cracking pattern. Experimental investigations which focus on the effect of the dimensions of aggregates over cracks are proposed in this paper. The samples are submitted to accelerated leaching or to drying, and the evolution of their microstructure is regularly recorded by means of X-ray microtomography. A method is then proposed to study the cracking pattern, which appears to be greatly dependant of the size of inclusions. In particular, it appears that a larger diameter of inclusions tends to increase the crack opening. DEWEY : 624 ISSN : 1964-8189 En ligne : http://ejece.revuesonline.com/resnum.jsp

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire