Treesearch

With most wood products being bonded with adhesives, it is important to understand failures. Although it is observed macroscopically, it originates microscopically.

Despite the importance of cell wall diffusion to nearly all aspects of wood utilization, diffusion mechanisms and the detailed effects of moisture remain poorly understood. In this perspective, we introduce and employ approaches established in polymer science to develop a phenomenological framework for understanding the effects of moisture on diffusion in unmodifed wood cell walls. The premise for applying this polymer-science-based approach to wood is that wood polymers (cellulose, hemicelluloses, and lignin) behave like typical solid polymers.Therefore, the movement of chemicals through...

Illegal logging and associated trade aggravate the over-exploitation of Swietenia species, of which S. macrophylla King, S. mahagoni (L.) Jacq, and S. humilis Zucc. have been listed in Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II. Implementation of CITES necessitates the development of efficient forensic tools to identify wood species accurately, and ideally ones readily deployable in wood anatomy laboratories across the world. Herein, a method using quantitative wood anatomy data in combination with machine learning models to discrimin...

Thermally modifed wood is becoming commercially available in North America for use in outdoor applications. While there have been many studies on how thermal modifcation affects the dimensional stability, water vapor sorption, and biodeterioration of wood, little is known about whether thermally modifed wood is corrosive to metal fasteners and hangers used to hold these members in place. As thermally modifed wood is used in outdoor applications, it has the potential to become wet which may lead to corrosion of embedded fasteners. Here, we examine the corrosiveness of thermally modifed ash...

Wood is a versatile and sustainable building material but may be vulnerable to fungal decay and insect damage when used outdoors or otherwise subjected to moisture. Pressure treatment with wood preservatives is the most common method of protecting wood from biological deterioration. This publication summarizes characteristics of pressure-treating preservatives and provides guidance for selection of pressure-treated wood for specific applications. It also discusses construction practices, service life expectations, and environmental considerations. The intended audience for this publication...

Computer vision systems for wood identifcation have the potential to empower both producer and consumer countries to combat illegal logging if they can be deployed effectively in the feld. In this work, carried out as part of an active international partnership with the support of UNIDO, we constructed and curated a feld-relevant image data set to train a classifer for wood identifcation of 15 commercial Ghanaian woods using the XyloTron system. We tested model performance in the laboratory, and then collected real-world feld performance data across multiple sites using multiple XyloTron...

In this paper, the behavior of an acoustic wave within an idealized wood specimen are compared and contrasted to the acoustic behavior observed in clear wood and lumber using signal processing and analysis. Published information on the physical and mechanical properties of clear, defect-free wood is used to derive a model of acoustic wave behavior. The model closely matches results observed from defect-free wood. Wave behavior is also examined in a series of wood specimens containing strength reducing defects such as knots and slope of grain. Differences between the idealized model results...

Two fluorescence-tagged carbohydrate-binding modules (CBMs), which specifically bind to crystalline (CBM2a-RRedX) and paracrystalline (CBM17-FITC) cellulose, were used to differentiate the supramolecular cellulose structures in bleached softwood Kraft fibers during enzyme-mediated hydrolysis. Differences in CBM adsorption were elucidated using confocal laser scanning microscopy (CLSM), and the structural changes occurring during enzymemediated deconstruction were quantified via the relative fluorescence intensities of the respective probes. It was apparent that a high degree of order...

Hygrothermal models are commonly used for prediction and evaluation of wall assembly moisture performance. Drying and redistribution of moisture are important to consider because they mitigate the effect of water intrusion during construction and throughout the service life of the building. In this study we compare simulations with measurements for two out of eight different residential wood-frame wall assemblies, in two orientations, with different kinds of insulation outboard of the oriented strand board (OSB) sheathing, in the cold climate of Madison, WI. Over two years we collected...

The use of mass timber structural products (such as glulam and cross-laminated timber) in commercial buildings is increasing in prevalence around the world. Whereas moisture management during the construction process is important for all building types, it is especially important for buildings with wood structural members. The exposure of mass timber products to the environment during construction can result in wetting of the wood, and mass timber products may take longer to dry than lightweight wood-frame construction. To better understand the moisture conditions to which mass timber...