Treesearch

In the building community, there is a growing demand for high-performance, low-maintenance, and low-cost building products. To meet this demand, natural fiberthermoplastic composites are being used to produce such products as decking, window and door elements, panels, roofing, and siding. In spite of the rapid growth in the use of these composites, little is known about their fastener performance. In this study, experimental fastener tests were performed on wood flour-thermoplastic composite panels. Results are presented for screw withdrawal, nail withdrawal, nail head pull-through, and...

CCA-treated southern yellow pine (SYP) chips were remediated utilizing acid extraction alone, and using acid extraction followed by bioleaching with the metal-tolerant bacterium Bacillus licheniformis CC01. bCleanedc chips were used to make particleboard (PB) with 10 percent urea-formaldehyde (UF) resin, and the PB samples were evaluated for internal bond (IB), modulus of elasticity (MOE), modulus of rupture (MOR), thickness swell (TS), water absorption, and decay resistance. PB panels prepared from just acid-extracted chips and two-step remediated chips showed an average 22 and 28 percent...

A key to 13 species in the genus Hygrocybe subgenus Pseudohygrocybe section Firmae is provided for the Greater Antilles. Seven new species and one species that is a new report for the Greater Antilles are described. The new species are H. brunneosquamosa, H. cinereofirma, H. flavocampanulata, H. luboyi, H. miniatofirma, H. neofirma and H. olivaceofirma. The new report is H. trinitensis.

Although timber production has grown steadily over the last decade, information about the use of timbers and the corresponding resource remains in short supply. This study adds to the available literature on solid sawn timbers by compiling data on timber production and uses. The major categories of solid sawn timbers researched were railroad ties, timber bridges, and other transportation structures. The outlook seems relatively bright for railroad ties. The demand for wood railroad ties has grown with the railroad industry, and there is no reason to think that this demand will not continue...

The production of industrial wood from natural forests is predicted to decline in the future. Factors that will contribute to this decline include changes in land use patterns, depletion of resources in some parts of the world, and the withdrawal of forest areas from industrial production in order to provide for environmental, recreational, and other social needs. There is a shortage of information on the suitability of fiber from many plantation-grown species for alternative composite products. This research was conducted to determine the suitability of plantation-grown Eucalyptus saligna...

Mildew resistance, water repellency, and overall finish appearance were evaluated for 32 deck finishes on western redcedar (Thuja plicata D. Donn.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) after 12, 21, and 39 months of outdoor exposure in western Oregon. The finishes were either solvent-borne or waterborne; were ei- ther clear, tinted, or lightly pigmented; and were, in general, formulated to penetrate the wood surface. Mildew resistance was generally good for most of the finishes through the 21-month evaluation. Water repellency was fair at the 12-month evaluation, but in...

Dowel bearing strength (embedment strength) is a critical component of wood connection design. Previous tests have concentrated on defining the relationship between dowel-bearing strength, specific gravity, and fastener characteristics such as diameter. However, because adoption of yield theory in defining connection strength is relatively new in the United States, few studies have been conducted that completely define the factors influencing dowel-bearing strength. One such factor is moisture content. In this study, the dowel-bearing strength of two groups of specimens was determined. One...

A practical method for tracking the effect of curtailment announcements on lumber supply is described and tested. Combining announcements of closures and curtailments with mill capacities enables the creation of accurate forward-looking assessments of lumber supply 1 to 2 months into the future. For three American and Canadian lumber- producing regions, the method produced projections of supply that were within 0.5 percent accuracy for a 7-month period encompassing June to December 2000. Announcements of production intentions are an important piece of market intelligence that can help...

Published information on estimated air-drying times of lumber is of limited usefulness because it is restricted to a specific location or to the time of year the lumber is stacked for drying. At best, these estimates give a wide range of possible times over a broad range of possible locations and stacking dates. In this paper, we describe a method for estimating air-drying times for specific locations by optimizing a drying simulation using existing experimental air-drying times for northern red oak, sugar maple, American beech, yellow-poplar, ponderosa pine, and Douglas-fir. The results...

The relationship between longitudinal stress wave transit time and wood moisture content (MC) was examined as a potential means of estimating MC control points in dry kiln schedules for lumber. A linear relationship was found between the relative transit time and the average MC of sugar maple and ponderosa pine boards dried according to typical kiln schedules.