Treesearch

Purpose: Global demand for construction materials has grown exponentially in the last century, contributing to climate change and detrimental impacts on the ecosystem. To aid in sustainable growth and reduce our environmental footprint, renewable construction materials, such as lumber, have been incorporated into green building activities. The purpose of this study was to quantify the environmental impacts associated with manufacturing redwood lumber in northern California using the life-cycle assessment (LCA) approach. Methods: This study surveyed and visited redwood manufacturing...

Global construction industry has a huge influence on world primary energy consumption, spending, and greenhouse gas (GHGs) emissions. To better understand these factors for mass timber construction, this work quantified the life cycle environmental and economic performances of a high-rise mass timber building in U.S. Pacific Northwest region through the use of life-cycle assessment (LCA) and life-cycle cost analysis (LCCA). Using the TRACI impact category method, the cradle-to-grave LCA results showed better environmental performances for the mass timber building relative to conventional...

Heartwood extracts of naturally durable wood species are often evaluated as alternatives to chemical wood preservatives, but field data from long-term performance testing are lacking. The current study evaluated the long-term (five-year) performance of two non-durable wood species treated with heartwood extracts of either Tectona grandis, Dalbergia sissoo, Cedrus deodara, or Pinus roxburghii alone or combined with linseed oil. Stakes (45.7 × 1.9 × 1.9 cm) and blocks (12.5 × 3.75 × 2.5 cm) cut from the sapwood of cottonwood and southern pine were vacuum-pressure impregnated with the...

Alternative specifcations of univariate asymmetric Laplace models are described and investigated. A more general mixture model is then introduced. Bivariate extensions of these models are discussed in some detail, with particular emphasis on associated parameter estimation strategies. Multivariate versions of the models are briefy introduced.

The Acetivibrio clariflavus (basonym: Clostridium clariflavum) glycoside hydrolase family 30 cellulosomal protein encoded by the Clocl_1795 gene was highly represented during growth on cellulosic substrates. In this report, the recombinantly expressed protein has been characterized and shown to be a non-reducing terminal (NRT)-specific xylobiohydrolase (AcXbh30A). Biochemical function, optimal biophysical parameters, and phylogeny were investigated. The findings indicate that AcXbh30A strictly cleaves xylobiose from the NRT up until an α-1,2-linked glucuronic acid (GA)-decorated xylose if...

The 2nd Mass Timber Research Needs Assessment Workshop was held on November 13-14, 2018 at the US Forest Service, Forest Products Laboratory (FPL). The purpose of the workshop was to convene a group of experts on cross laminated timber and mass timber to develop a list of prioritized research needs for the North American mass timber industry. The workshop had over 100 attendees including design professionals, academics, industry leaders, and government employees. The attendees generated a list of over 117 research needs. After the workshop, the list of 117 research needs was prioritized...

Water vapor sorption is an important characteristic of wood as an engineering material. In addition to affecting engineering properties such as the heat capacity, thermal conductivity, strength, stiffness, and dimensions, moisture is fundamental to many wood degradation mechanisms including fungal decay. Water vapor sorption isotherms have been gaining increasing attention in the wood literature as more laboratories adopt automated sorption balances, frequently called dynamic vapor sorption (DVS) analyzers. With DVS, the collection of sorption isotherms can be automated, completely...

The fire resistance of a structural building member includes its ability to survive a specified fire without loss of its loadbearing function. For glue laminated timber columns, fire resistance is determined by either subjecting a structural member to a standard fire test or by using one of two accepted calculation methods. For wood structural members, the calculation methods rely on char rates obtained from numerous standard fire tests. The existing calculation methods are limited under United States building codes to calculating fire resistance ratings of 120 minutes or less. However,...

This paper examines how the moisture conditioning method affects the electrical conductance of wood. A widely used dataset was acquired by Stamm in 1929 who used a method of conditioning where water-saturated wood specimens were partially dried, sealed and left for a period of time for moisture to be redistributed before the electrical conductance was measured. However, more recent measurements combined conditioning above saturated salt solutions and pressure plate/pressure membrane techniques to obtain equilibrium moisture contents at constant relative humidity levels in the full moisture...

Deep eutectic solvent treatment to overcome lignocellulose resistance to deconstruction has great potential for the production of biofuels and bioproducts. Most investigations have been focused on optimizing the sugar yield from specific feedstocks. However, little is known about the interaction between deep eutectic solvent and cellulose during pretreatment, post-treatment cellulose accessibility to enzymes, and lignin fractionation. We evaluated four deep eutectic solvents that consisted of choline chloride and biomass-derived polyols (ethylene glycol, glycerol, xylitol, and sorbitol)....