Documents disponibles écrits par cet auteur

Crack effects on gas and water permeability of concretes / Vincent Picandet in Cement and concrete research, Vol. 39 N° 6 (Juin 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 6 (Juin 2009) . - pp. 537–547 Titre : Crack effects on gas and water permeability of concretes Type de document : texte imprimé Auteurs : Vincent Picandet, Auteur ; Abdelhafid Khelidj, Auteur ; Hervé Bellegou, Auteur Année de publication : 2009 Article en page(s) : pp. 537–547 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Permeability;  Microcracking;  Durability;  High-performance  oncrete;  Fiber  reinforcement Résumé : The relationship between load-induced cracking and concrete permeability is studied. Ordinary concrete (OC) and high-performance concrete (HPC), including steel fiber-reinforced concrete (HPFRC), are used. Two discs, 50 mm-thick slices, cut from 110–220 mm cylindrical specimens are diametrically loaded, as for a normal splitting test. The lateral displacement, also called the crack opening displacement (COD) is monitored for each loading cycle. After unloading, gas and finally water permeability tests are both performed, using constant head permeameter, to compare the influence of the percolating fluid and the COD. Due to the wide range of measured gas flow, Klinkenberg's and Dupuit-Forcheimer's laws are applied to compute the intrinsic gas permeability. Results suggest it increases proportionally to the cube of the COD and it matches water permeability, if only the first water percolating time is considered. The roughness parameter of the cracks induced in each concrete, is compared and discussed. REFERENCE : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000696 [article] Crack effects on gas and water permeability of concretes [texte imprimé] / Vincent Picandet, Auteur ; Abdelhafid Khelidj, Auteur ; Hervé Bellegou, Auteur . - 2009 . - pp. 537–547. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 6 (Juin 2009) . - pp. 537–547 Mots-clés : Permeability;  Microcracking;  Durability;  High-performance  oncrete;  Fiber  reinforcement Résumé : The relationship between load-induced cracking and concrete permeability is studied. Ordinary concrete (OC) and high-performance concrete (HPC), including steel fiber-reinforced concrete (HPFRC), are used. Two discs, 50 mm-thick slices, cut from 110–220 mm cylindrical specimens are diametrically loaded, as for a normal splitting test. The lateral displacement, also called the crack opening displacement (COD) is monitored for each loading cycle. After unloading, gas and finally water permeability tests are both performed, using constant head permeameter, to compare the influence of the percolating fluid and the COD. Due to the wide range of measured gas flow, Klinkenberg's and Dupuit-Forcheimer's laws are applied to compute the intrinsic gas permeability. Results suggest it increases proportionally to the cube of the COD and it matches water permeability, if only the first water percolating time is considered. The roughness parameter of the cracks induced in each concrete, is compared and discussed. REFERENCE : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000696

Effect of compaction on mechanical and thermal properties of hemp concrete / Tai Thu Nguyen in European journal of environmental and civil engineering, Vol. 14 N° 5 (Mai 2010) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 14 N° 5 (Mai 2010) . - pp. 545-560 Titre : Effect of compaction on mechanical and thermal properties of hemp concrete Type de document : texte imprimé Auteurs : Tai Thu Nguyen, Auteur ; Vincent Picandet, Auteur ; Patrick Carre, Auteur Année de publication : 2011 Article en page(s) : pp. 545-560 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Hemp  Lime  Sustainable  building  Green  materials  Thermal  insulation  Mechanical  behaviour Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Some preliminary studies, dealing with the process optimisation of pre-cast building elements made of Lime and Hemp Concrete (LHC), have shown that compression during casting lead to significant improvements: better mechanical characteristics and facing. However, this compaction leads to an increase of the weight to volume ratio and to a decrease in porous volume. Thus, the amount of entrapped air inside material, which contributes to decrease the thermal conductivity, is lower. Our data actually show a slight increase in thermal conductivity when compactness increases. The goal of this study is to compare the effect of compaction during casting on both mechanical and thermal characteristics of hardened specimens in order to evaluate the relevance of such a process. DEWEY : 624 ISSN : 1964-8189 En ligne : http://ejece.revuesonline.com/resnum.jsp [article] Effect of compaction on mechanical and thermal properties of hemp concrete [texte imprimé] / Tai Thu Nguyen, Auteur ; Vincent Picandet, Auteur ; Patrick Carre, Auteur . - 2011 . - pp. 545-560. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 14 N° 5 (Mai 2010) . - pp. 545-560 Mots-clés : Hemp  Lime  Sustainable  building  Green  materials  Thermal  insulation  Mechanical  behaviour Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Some preliminary studies, dealing with the process optimisation of pre-cast building elements made of Lime and Hemp Concrete (LHC), have shown that compression during casting lead to significant improvements: better mechanical characteristics and facing. However, this compaction leads to an increase of the weight to volume ratio and to a decrease in porous volume. Thus, the amount of entrapped air inside material, which contributes to decrease the thermal conductivity, is lower. Our data actually show a slight increase in thermal conductivity when compactness increases. The goal of this study is to compare the effect of compaction during casting on both mechanical and thermal characteristics of hardened specimens in order to evaluate the relevance of such a process. DEWEY : 624 ISSN : 1964-8189 En ligne : http://ejece.revuesonline.com/resnum.jsp