Treesearch

Summarizes information on wood as an engineering material. Presents properties of wood and wood-based products of particular concern to the architect and engineer. Includes discussion of designing with wood and wood-based products along with some pertinent uses.

Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which are important to understand in order to optimize their applications. In this investigation, the structures of CNCs produced upon 48–64% H2SO4 hydrolysis of hydrothermally-treated poplar, bleached kraft pulp cotton microcrystalline cellulose, bacterial cellulose, tunicin, and cladophora cellulose were comparatively analyzed. TEM provided information on the morphological aspects. Raman, MAS-NMR, and XRD provided information on one aspect of the supramolecular organization, namely, crystallinity...

Brown rot fungi utilize iron as part of a chelator-mediated Fenton (CMF) reaction during wood biodegradation. Research suggests these fungi reduce Fe3+ to promote oxygen radical generation resulting in depolymerization of the wood cell wall. High levels of Mn are also found in wood decayed by brown rot fungi. However, little is known about the oxidation states of Fe and Mn during the decay process. X-ray absorption near edge spectroscopy (XANES) can be used to examine metal oxidation states and coordination chemistry. XANES experiments were conducted on wood decayed by Gloeophyllum trabeum...

In October, the aggregate U.S. housing market was mixed. Assessing the month-over-month data yielded decreases for multifamily permits and under construction, all three completion categories, and new single-family sales. Year-over-year, most categories were positive, with the exceptions of multifamily starts and permits, and single-family completions. Residential construction spending was positive month-over-month and year-over-year; and expenditures in August, September, and October are the greatest since the residential surge of 2005–2006. Housing remains a bright spot for the U.S. economy.

In November, the aggregate (month-over-month and year-over-year) U.S. housing market indicators were positive. November housing data denoted the second consecutive month of total starts greater than 1.5-million units. The single-family subsector is the primary source of the current uptrend and is progressively gaining momentum. Month-over-month data yielded decreases in four categories: total and multifamily completions, new single-family and existing sales. Similarly, year-over-year data indicated declines for multifamily starts and permits, and total and single-family completions....

December housing data denoted the second consecutive month of total starts greater than 1.5 million units. For the fourth consecutive month, total starts exceeded their 61-year historical average. Further, single-family starts were the greatest since September 2006 (1,384,000 units). Aggregate (month-over-month and year-over-year) U.S. housing market data also were positive. The single-family subsector is the primary source of the current uptrend and is progressively gaining momentum. Month-over-month data yielded decreases in three categories: aggregate multifamily starts and permits, and...

The first research on acetylation of wood started in 1928, and the first research done on acetylation of wood at the USDA Forest Service Forest Products Laboratory (FPL) started in 1945. This is a review of the research done between 1945 and 1966 at the FPL. This research was the first to show that acetylated wood was both decay-resistant and dimensionally stable. It was the pioneering research that ultimately led to the commercial production of acetylated wood.

This paper examines the strength of wood adhesive bonds at high temperatures. The goal of this research is to better understand the conditions of heat delamination in cross laminated timber (CLT) that is exposed to fire. Heat delamination in CLT occurs when one lamination detaches from the composite panel before the char front reaches the bondline. Timber that falls from the panel, as a result of delamination, contributes additional fuel to the fire, which can cause fire regrowth, while the loss of a lamination causes a sudden loss in strength. Currently, to demonstrate that an adhesive...

This research presents the development of a mass timber buckling restrained brace (T-BRB) that combines a low yield strength steel core with a mass timber casing to create a new ductile fuse. The T-BRB is an essential element of a mass timber buckling restrained braced frame (BRBF), which is a promising mass timber wood lateral force–resisting system. Critical elements of T-BRB design that are important for good performance include casing stiffness, casing material, number and spacing of bolts, timber spacer and casing gap, steel core yield strength, and friction between steel core and...

Synthetic polymers are ubiquitous materials widely used in construction, automotive, electronics, and countless commercial products. With the growing trend of polymer applications in everyday life, upholding the rigorous fire safety regulations has become a matter of concern. In this regard, numerous studies have been conducted for improving the fire retardancy of polymers, mainly through incorporating a diverse group of fire-retardant compounds into polymer-based composites. This review article aims to present a comprehensive overview of recent advances in the fire-retardant categories...