Treesearch

This study was undertaken to examine the relationship between lumber grain angle and the energy loss characteristics of structural lumber. A random sample of 100 spruce–pine–fir lumber specimens was obtained from a local lumber yard. Grain angle was measured at numerous locations for each specimen with equipment that uses a dielectric nondestructive testing technique. A commonly used free transverse vibration test, in which the specimens were simply supported in a flatwise bending mode, was used to determine the energy loss characteristics of the specimens. Increases in grain angle...

AbstractThe study summarized in this research note was conducted to examine the relationships between nondestructive evaluation (NDE) parameters, tensile modulus of elasticity (MOE), and strength of spruce–pine–fir structural lumber. Samples were procured from a local lumber yard using a random selection process and were conditioned at the USDA Forest Service, Forest Products Laboratory, to 10% equilibrium moisture content. Static bending and vibration (transverse and longitudinal) nondestructive tests were conducted on each specimen and MOE was calculated. The relationship between static...

Fetterbush (Lyonia lucida) grows in the southern states of the United States. The chemical components in fetterbush are highly concentrated with phenolic compounds. These compounds contribute to the toxicity of the plant and could possibly be igniters for wildfire. In this study, liquid extractions were obtained from fresh Fetterbush samples. Two-dimensional gas chromatography and time of flight mass spectrometry (GC×GC-TOFMS 4D) were used to characterize the chemical compositions in the liquid extractions. GC×GC technology has existed for more than 30 years. This technique opens the peak...

Black locust (Robinia pseudoacacia) is a native tree in southeastern United States. The wood from this tree is known for resistance to decay and excellent longevity even in soil contact. It is a durable species used for fence post material. It is also known for the stilbene chemicals resveratrol and piceatannol. These chemicals exhibit biological activities, mainly antioxidant properties. Identifying the chemicals that contribute to the durability of black locust could lead to the development of relevant medicinal alternatives and other products. In this study, black locust wood and bark...

Cross laminated timber (CLT) is becoming widely available in North America. The product standard for North American CLT, PRG-320, has strict requirements on adhesive performance under fire scenarios. To become an adhesive certified under PRG-320, a full sized CLT compartment must be built and tested without a second flashover occurring caused by delamination. Currently, only three adhesive formulations are PRG-320 certified. This large scale test is expensive to run and only yields “pass-fail” results. In this paper we present small-scale adhesive tests performed at the Forest Products...

AbstractNondestructive evaluation procedures are now widely used in the forest products industry. These procedures rely upon nondestructive tests to evaluate important physical and mechanical properties of wood-based materials and began with fundamental research during and after World War II. An important outcome was the evolution of machinery and process for grading lumber and veneer. A dedicated group of scientists and engineers conducted and adapted this research for industrial use and developed equipment to make accurate measurements of wood properties in a production setting. One of...

As heat is applied to wood, thermal degradation, called pyrolysis, occurs. A majority of what is known about the pyrolysis of wood has been obtained using either extracted component polymers or wood pyrolyzed in an inert atmosphere. However, the physical and chemical reactions that occur during pyrolysis of wood are affected by the interaction of the polymers in whole wood as well as the oxygen present in the atmosphere. X-ray photoelectron spectroscopy (XPS) is a surface measurement technique that yields information on both the chemical composition of the sample and the chemical bonds...

Although international regulations have been successfully implemented to reduce the introduction and spread of plant pests through wood packaging material (WPM), wood-boring insects continue to be intercepted in WPM at U.S. ports of entry. Both hardwoods and softwoods are used in the construction of WPM for international trade; however, it is not clear if some types of wood pose higher risks than others for harboring wood borers. This study documented the taxonomic diversity of infested wood genera intercepted as a result of targeted WPM inspection at U.S. ports, and identifed many of the...

Acetylated wood is now commercially available and designed to be used in certain outdoor applications as an alternative to preservative-treated wood. Fastener corrosion can be a concern in preservative treated wood when the wood remains wet for long periods. However, little data on the corrosiveness of acetylated wood exists beyond the product literature. Here we examine the corrosiveness of commercially obtained acetylated wood and compare it against unmodified (untreated) southern pine (Pinus spp.). Corrosion rates of plain carbon steel, hot dip galvanized steel, and stainless steel were...

Cross laminated timber (CLT) is becoming more widely available in North America. However, it has not yet achieved widespread use in construction in the United States because provisions for CLT have only recently been added to model building codes. For example, CLT was recognized for the first time in the 2015 International Building Code (IBC), and the 2021 IBC will allow wood buildings made of CLT and other types of mass timber to be constructed up to 18 stories high. The changes to the 2021 IBC were implemented after several years of work from an ICC Ad-Hoc committee on tall wood buildings...