Personne :
Blanchet, Pierre

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Université Laval. Département des sciences du bois et de la forêt
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Voici les éléments 1 - 10 sur 102
  • Publication
    Wood degradation under UV irradiation : a lignin characterization
    (Elsevier, 2016-03-06) Landry, Véronic; Cogulet, Antoine; Blanchet, Pierre
    The photodegradation of white spruce by artificial ageing was studied by several techniques: colourimetry, FTIRATR and FT-Raman spectroscopy. Samples were exposed at a xenon lamp for 2000 h. Two distinct colour changes were found by colourimetric analysis, yellowing and silvering. These colour modifications indicate the formation of chromophoric structures which supports previous FTIR-ATR experiments. The degradation of lignin to generate the first chromophoric group for yellowing and then the appearance of surface layer cellulose. New carbonyl compounds conjugated with double bond at 1615 cm-1 are probably the second chromophoric group. The crystallinity index was also calculated and showed an increase of cellulose crystallinity by prior degradation of amorphous cellulose. The FT-Raman analysis confirms the wood sensitivity to photodegradation but the most remarkable results is the increase of fluorescence as a function of time. In softwood lignin, the compound able to produce fluorescence is a free rotating 5–5' linkage of one biphenyl structure. At native state these linkages are not free rotating, this phenomenon means the release of 5–5' linkage of lignin structure by cleavage of both a carbon linkages (Norrish type I reaction). These data confirm also the photosensitivity of a and ß carbon in lignin and the resistance of 5–5' linkages.
  • Publication
    Accès libre
    Impact of a reinforcement treatment with acrylate impregnation on the mechanical behavior of black spruce as connector member.
    (Elsevier, 2017-03-14) Lafond, Cassandra; Galimard, Philippe; Landry, Véronic; Blanchet, Pierre; Ménard, Sylvain
    As a previous study has shown, it is possible to increase by 50% the dowel bearing strength of black spruce with an acrylate formulation applied by impregnation. Three diameters of bolts and two orientations of loading were included in this study. The effect of treatment on the dowel-bearing strength appeared to increase while the diameter of bolt decreased. The orientation of loading was significant as the treatment had a major impact in the parallel to grain direction and no impact in the perpendicular direction. With the digital image correlation analysis, an expanded strain field perpendicular to the load direction was observed. The superior embedding capacity would help to reduce the dimensions of the timbers as well as the number of connections required in the building design. With an increase of ductility, wood connections show a safer yielding behavior.
  • Publication
    Accès libre
    Maleic anhydride treated wood : effects of drying time and esterification temperature on properties
    (Dept. of Wood and Paper Science, College of Natural Resources, North Carolina State University, 2015-08-26) Essoua Essoua, Gatien Géraud; Landry, Véronic; Beauregard L., Robert; Blanchet, Pierre
    To improve technical performance of wood siding, treatment with maleic anhydride was applied. The effects on technical performance of drying time and esterification temperature parameters were analyzed. Wood samples of lodgepole pine and white pine were treated and tested. Results indicated that treatment improves technical performance of wood (dimensional stability, fungal degradation resistance, and accelerated aging). FTIR spectroscopy analysis showed spectra with peaks at 1750 to 1730 cm-1. These correspond to ester bonds formed between wood hydroxyl groups and MA carboxylic groups. SEM images indicate that the MA quantity in wood cavities was increased with decreasing esterification temperature. Weight percent gain (WPG) increased with decreasing time and temperature of esterification. Artificial aging and fungal degradation performances were monitored using FTIR analysis. Esterification temperature had no important effect on fungal degradation. Weight loss after fungal exposure of treated samples was not only due to fungal action but also due to evaporation of MA during the drying step. Regarding artificial aging, degradation of wood components and ester bonds were less for samples esterified at 180 °C than those esterified at 160 °C or 140 °C.
  • Publication
    Accès libre
    Impact of indoor use of wood on the quality of Interior ambiances under overcast and clear skies : case study of the Eugene H. Kruger Building, Québec city
    (Dept. of Wood and Paper Science, College of Natural Resources, North Carolina State University, 2016-01-06) Demers, Claude; Landry, Véronic; Jafarian, Hoda; Blanchet, Pierre
    This paper explores the potential of wood for improving environmental quality in interior spaces. In northern climate cities where overcast skies predominate, interior spaces may appear gloomy or dull, since natural light is white and uniform. Nevertheless it is observed that wooden surfaces tend to create warmer and brighter spaces under overcast sky conditions. The objectives of this research were twofold. The first was evaluating the quality of wooden spaces under two sky conditions in terms of color, brightness and contrast. The second objective was to investigate daylight quantity of wooden spaces under diffuse and clear sky conditions. The method involved on site-surveys using Photolux, a calibrated photoluminance meter. Data consist of calibrated digital images that were processed to analyze the quality of spaces based on brightness, contrast, and color. The Kruger Building, with its internal wooden architectural structure and decorative indoor panels, was chosen as a site study for this research. Conclusions suggest that knowing the effect of different sky conditions on wooden spaces can help architects and other professionals in designing more comfortable and efficient ambiances. More particularly, this research addresses issues related to the quantitative effects of wood on daylighting distribution, visual comfort and luminance diversity
  • Publication
    Accès libre
    UV-LED curing efficiency of wood coatings
    (MDPI, 2015-12-18) Bouffard, Jean-François.; Boivin, Gabrielle; Landry, Véronic; Vlad-Cristea, Mirela Simona; Blanchet, Pierre
    Ultraviolet light emitting diodes (UV-LEDs) have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerful enough to cure UV high solids acrylate coatings while satisfactory results can be obtained for UV water-based formulations. In fact, conversion percentages were found to be low for the high solids coatings, leaving the coatings tacky. Higher conversion percentages were obtained for the UV water-based formulations. As a result, mass loss, hardness, and scratch resistance found for the samples cured by UV-LED were closed to the ones found for the samples cured using the UV microwave lamp.
  • Publication
    Prospects for appearance wood products ecodesign in the context of nonresidential applications
    (Forest Product Society, 2016-08-18) Beauregard L., Robert; Cobut, Aline; Blanchet, Pierre
    As environmental awareness grows, societal demand for more environmentally friendly products increases. Demand for environmental responsibility also reached the building material and construction sector. Green building has become more widespread over the past decade and can be considered a challenge for specifiers and building products manufacturers. Ecodesign, an application of the sustainable development concept, is one of the available tools to address this challenge. This article aims at proposing an ecodesign pathway for appearance wood products in the nonresidential building sector. Through extrapolating results from a previous interior wood door case study, it has been possible to obtain environmental profiles for the main segments of the appearance wood products family for nonresidential buildings. These profiles have allowed devising ecodesign solutions. Results show that for this whole family of products, raw materials are what cause the most environmental impacts, followed by shipping and end-of-life stages. Product component weight tends also to influence the environmental profile. Ecodesign solutions for composite-based products are strongly related to decreasing the composite component weight by design and remanufacturing. For solid wood–based products, ecodesign can be approached through remanufacturing or reclaiming, using locally certified sustainable wood. The use of hardwood waste may be available for energy purposes, but this may not be as relevant as reuse and recycle in the context of the province of Quebec energy grid mix.
  • Publication
    Accès libre
    Reducing the environmental footprint of interior wood doors in non-residential buildings - part 2 : ecodesign
    (Butterworth-Heinemann, 2015-05-25) Beauregard L., Robert; Cobut, Aline; Blanchet, Pierre
    Ecodesign is a concept that emerged few decades ago as a response to the larger concept of sustainable development. Multiple tools exist to address ecodesign. Life Cycle Assessment, a comprehensive, robust and recognized evaluation tool, enables to identify the product environmental profile. Based on previous LCA results on interior wood doors, this paper aims at proposing an ecodesign strategy based on the generation and evaluation of alternative scenarios. The three selected targets for environmental improvement are particleboard components, transportation and end-of-life. For the particleboard manufacturing, the use of adhesives based on bio-sourced resources was not very conclusive, except for the use of pine tannins in panel manufacture that showed promising results. Concerning transportation issues, switching from road to rail transportation, as well as having a local supplier, decreased the overall environmental impact of the door. The most notable alternative was the end-of-life recycling scenario. The reutilization of the door core in the door manufacturing process proved a great benefit due to the avoidance of new raw materials production. Developing services around door recovery and remanufacturing seems promising in reducing doors environmental impacts. This scenario would be readily viable and realistic.
  • Publication
    Accès libre
    The environmental footprint of interior wood doors in non-residential buildings. part 1, Life cycle assessment
    (Butterworth-Heinemann, 2015-04-30) Beauregard L., Robert; Cobut, Aline; Blanchet, Pierre
    Integrating environmental aspects into industrial practices has become a necessity. In fact, climate change and resource depletion have been established scientifically and can no more be neglected. Life Cycle Assessment is acknowledged to be an efficient tool to establish a product environmental profile and can be useful to businesses wishing to analyze their environmental record. Decreasing a building environmental footprint implies, among other considerations, a proper choice of building materials, both structural and architectural. A good avenue would be to select low environmental impact materials from cradle-to-grave. Architectural wooden doors are often specified in non-residential buildings in North America. However, only one Life Cycle Assessment has been carried out on wooden doors. This study explores the cradle-to-grave environmental profile of an interior wood door in a North American context. According to the results, the main contributor to the product impacts is the production of raw materials, especially the particleboard component, and their transportation to the manufacturing plant. The urea formaldehyde production is the main reason for particleboard impacts among the three damage categories, human health, climate change and resources, of IMPACT 2002+. The other life cycle stages that have a noticeable influence on the door environmental impacts are shipping and end-of-life. Transportation as a whole affected the system total environmental score. The current results could serve as a basis for ecodesign implementation.
  • Publication
    Using life cycle thinking to analyze environmental labeling : the case of appearance wood products
    (Spinger, 2012-09-25) Beauregard L., Robert; Cobut, Aline; Blanchet, Pierre
    Purpose: Growing public concern about the current state of our planet led to the creation of numerous regulations, standards, and certifications for the protection of humans and the environment. Ecolabels were defined for products such as cleaning products, paints, and many others. Wood building products are no exception. The objective of this study is to analyze the existing ecolabelling programs for appearance wood products in nonresidential applications and to evaluate them relatively to their effective role in environment protection or reduction of environment footprint. Methods: The research was conducted on the most common International Organization for Standardization (ISO) type I ecolabels in North America, the European Union, and Japan. Certification schemes applicable to appearance wood products for nonresidential applications were considered. In a life cycle assessment perspective, certification criteria were compared regarding their ability to consider and integrate environment impacts. Results and discussion: A wide range of ecolabels can apply to appearance wood products, from indoor air quality to wood from sustainable forest management. Moreover, it has been found that among all certification schemes studied, those integrating the whole life cycle were the most relevant. Conclusions: The remaining limitation of ISO type I ecolabels is the lack of environmental information enabling the differentiation between products bearing the same ecolabel. This can be overcome by ISO type III environmental product declarations. Thus, allowing a better understanding of the implications related with the use of wood products compared to other materials in the nonresidential building sector.
  • Publication
    Accès libre
    Caractérisation du comportement des lames de plancher d'ingénierie
    (2004) Blanchet, Pierre; Gendron, Guy; Cloutier, Alain; Beauregard L., Robert
    Le développement de produits du bois transformés ou à valeur ajoutée se présente comme une opportunité importante de tirer profit des ressources naturelles canadiennes et du savoir-faire de l'industrie de transformation des produits du bois. L'utilisation optimale de la ressource forestière en des produits transformés est une avenue s'inscrivant dans le concept de produits du bois à valeur ajoutée. Les lames de plancher d'ingénierie sont un exemple de cette situation. Le produit se compose d'une planchette de surface de grande qualité, d'un substrat et occasionnellement d'une couche de contrebalancement. Pour un composant de bois de 4/4 d'épaisseur destiné à la fabrication de lames de plancher traditionnelles en bois massif, 4 ou 5 planchettes de surface destinées à la fabrication d'autant de lames de plancher d'ingénierie seront produites. De plus, l'usage des bois de faible qualité comme substrat est possible et c'est l'approche qui a été favorisée dans ce travail. Le produit se démarque sur les marchés européen et américain. En 2002 aux États-Unis, ce sont 58 % des revêtements de sol en bois qui étaient des lames de plancher d'ingénierie. En Europe, en 2001, 73 % des revêtements de plancher en bois étaient des planchers d'ingénierie. Ces situations sont issues d'un contexte de croissance du produit depuis les 10 dernières années. Ce projet avait pour objectif général d'augmenter et de préciser la connaissance sur le comportement et les performances des planchers d'ingénierie fabriqués à base de matériaux canadiens et mis en service dans les conditions atmosphériques nord-américaines afin d'améliorer le design de ces planchers. Plus spécifiquement, ce projet avait pour objectifs : de développer des prototypes à base de matériaux canadiens et documenter leur comportement, d'établir les critères de performance des lames de planchers d'ingénierie, d'établir un modèle mécanique du comportement des parquets d'ingénierie et de définir les paramètres de design responsables de la bonne performance des parquets d'ingénierie à l'aide de différentes modélisations et de validations expérimentales. Dans un premier temps, des prototypes ont été réalisés et testés en chambres climatisées. À cette étape du projet, l'acquisition de connaissances sur le sujet était prioritaire. Incidemment, un critère de performance fut établi de même qu'une méthodologie pour faire la comparaison de la performance de différentes constructions de lames de plancher d'ingénierie. Le matériau utilisé comme substrat a eu un impact important sur la performance observée. L'utilisation d'une couche de contrebalancement a aussi eu un impact notable. Dans un second temps, l'approche de modélisation par la méthode des éléments finis fut utilisée pour obtenir des prédictions du comportement des lames de plancher d'ingénierie précédemment évaluées en laboratoire. Ainsi, certains paramètres moins bien documentés ont été modulés afin d'observer leur impact sur le modèle. Ensuite, les résultats expérimentaux de la construction faite de 4 mm d'épaisseur de couche de surface en érable à sucre, de 8 mm d'épaisseur de substrat en bouleau blanc et de 2 mm d'épaisseur de couche de contrebalancement en bouleau jaune ont été reproduits avec succès. Enfin, le modèle fut utilisé pour une étude de la géométrie et des espèces utilisées dans le substrat. Il est apparu que la nature du substrat est importante. Plus les propriétés mécaniques du matériau augmentent, moins importante est la déformation de tirant à c?ur, le principal critère de performance. L'épaisseur du substrat est apparue également comme un levier important afin de contrôler la déformation dans les lames de plancher d'ingénierie.