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.

In North America, most housing and commercial structures built prior to the 20th century used wood as the major structural material. The abundant wood resource formed the basic structure for most houses, commercial buildings, bridges, and utility poles. Today, houses and many light commercial and industrial buildings are made using modern wood structural materials. Recently, there has been increased interest in using wood for various types of transportation structures, including bridges. In this chapter, the features of various types of building systems are described. Emphasis is placed on...

Cone calorimeter tests of wood with three different backings showed that the backing did not affect time to ignition, initial peak heat release rate (HRR), and total heat release, at four different imposed heat fluxes. However, use of dense backing board for the Steiner tunnel test eliminated the second peak in the HRR profile and prolonged the intervening period of simultaneous flaming and glowing combustion, as evidenced by a gradual increase in the heat of combustion with time. Gypsum backing board had an intermediate effect on the HRR profile. The volatile and glowing effective heats...

This study verifies a single-stage reaction-rate model for the long-term effects of various fire retardants. The adequacy of predictions from our previously reported models was tested using data from fire-retardant-treated wood exposed at 66°C (150°F) and 75% relative humidity for 3 or 4 years. Our analysis showed that if the treated wood experienced significant thermal degradation early during exposure to high temperature, then the previously reported model parameters adequately predicted thermal degradation for up to 4 years of steady-state exposure. However, if the treated wood did not...

A predictor sort experiment is one in which experimental units are allocated on the basis of the values of a predictor variable that is correlated with the response. Standard ANOVA analyses of predictor sort experiments can lead to confidence intervals whose actual coverages are poor matches to nominal coverages. Correct coverages can be obtained by adjusting confidence interval lengths by appropriate factors, or by performing analyses of covariance.

Research at the USDA Forest Service, Forest Products Laboratory (FPL) is being conducted to identify the compounds emitted from wood products during their manufacture and subsequent use. The FPL researchers are measuring the types and quantities of VOCs that are emitted from particleboard and MDF products to provide quantitative emissions information. This information can be used by other researchers studying indoor air quality of homes and offices where these products are used. The FPL researchers are also evaluating emissions during the manufacture of various composite wood products....

A rare find of Calocybe cyanea from Puerto Rico is described and illustrated. A discussion of all species of Calocybe found in the Caribbean is provided. Since nearly one-half of the described species of Calocybe can be found in the Neotropics (nine out of the 20 or so known taxa), a key to the species of Calocybe which are found in the Neotropics is included.

The degradation of wood by decay, fire and UV constitutes the three major losses of wood products in use. Commercial wood preservatives including chromated copper arsenate(CCA) and pentachlorophenol(penta) can only protect wood from decay. Dual protections of wood against decay and fire or decay and UV if acheivable are more desirable. Many phosphorus and boron compounds posses fire retardant and decay resistant properties. In our previous investigation, we found that wood reacted with phosphoramides produced in situ by reacting phosphorus pentoxide with amines was able to protect wood...

Charring rates for large-section timber based on experimental data have been generally established. The established rates may not be appropriately used for the prediction of failure times of lumber members which are small by comparison. It is questionable whether a constant rate can be safely assumed for lumber members since the rate is likely to increase once the centre-point temperature of the members stats to rise. This paper presents an empirically based model of charring rates for Spruce-Pine-Fir (SPF) Machine-Stress-Rated (MSR) 2 × 4 lumber subject to a constant-temperature exposure...

Adhesive bonding of wood components has played an essential role in the development and growth of the forest products industry and has been a key factor in the efficient utilization of our timber resource. The largest use of adhesives is in the construction industry. By far, the largest amounts of adhesives are used to manufacture building materials, such as plywood, structural flakeboards, particleboards, fiberboards, structural framing and timbers, architectural doors, windows and frames, factory- aminated wood products, and glass fiber insulation. Adhesives are used in smaller amounts...