Treesearch

The aim of this study was to evaluate the change in colorimetric patterns and the termite resistance of lightcolored and low durability wood when impregnated with teak (Tectona grandis) heartwood extractives. Hot water and ethanol extracts were obtained from 20-year-old teak heartwood and used to evaluate the influence on color change and the natural resistance of 10-year-old teak sapwood and Pinus sp. For wood impregnation, a full-cell (Bethell) treatment was conducted. To verify the influence of the teak extracts, the colorimetric patterns of wood were determined using the Munsell and...

This study evaluated the effect of wood extracts from Tectona grandis, Dalbergia sissoo, Cedrus deodara, and Pinus roxburghii combined with linseed oil as protectants of two non-durable wood species against the termite, Heterotermes indicola. Heartwood blocks (19 × 19 × 19 mm) and wood shavings were extracted using an ethanol/toluene (2:1) solvent system. Results of choice and no-choice tests with solvent-extracted and non-extracted heartwood blocks showed greater wood mass loss from termite feeding on solvent-extracted blocks compared with non-extracted blocks for all wood species....

Wood extractives are considered the major factor determining the natural durability of wood. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was assessed for rapid determination of western juniper (Juniperus occidentalis Hook. var. occidentalis) durability based on extractives in heartwood, sapwood-heartwood and sapwood regions. Durability was assessed by exposing samples to brown-rot decay fungi [Gloeophyllum trabeum (Pers.) Murrill and Rhodonia placenta (Fr.) Niemelä, K.H. Larss. & Schigel] or eastern subterranean termite (Reticulitermes flavipes Kollar)....

This report summarizes information on the use of wood from hardwood species in engineered materials, components, and structures. It includes information on use in a wide variety of engineering products and applications.

The feasibility of manufacturing cross-laminated timber (CLT) from southern yellow pine (United States grown) treated with micronized copper azole type C (MCA-C) preservative was evaluated. Lumber (2x6 visually graded no. 2 boards) was treated to two retention levels (1.0 and 2.4 kg/m3 ), planed to a thickness of 35 mm, and assembled along with an untreated control group using three adhesive systems following product specifications: melamine formaldehyde (MF), resorcinol formaldehyde (RF), and one-component polyurethane (PUR). Block shear and delamination tests were conducted to examine...

Cross-laminated timber (CLT) manufacturing and construction has been steadily growing since its inception in Europe in the 1990s. In the US, the growth of the CLT adoption is inhibited by the lack of codified design provisions for CLT in high seismic regions. This led to a multi-year study conducted by Colorado State University to investigate suitable seismic design parameters of CLT shear wall systems. This paper presents the results from a series of shake-table tests featuring a full-scale two-story mass-timber building utilizing CLT Seismic Force Resisting Systems (SFRS). The building...

The 21st International Nondestructive Testing and Evaluation of Wood Symposium was hosted by the Forest Research Institute Baden-Württemberg (FVA) in Freiburg, Baden-Württemberg, Germany, September 24–27, 2019. This symposium was a forum for those involved in nondestructive testing and evaluation (NDT/NDE) of wood and brought together many international researchers, NDT/NDE users, suppliers, representatives from various government agencies, and other groups to share research results, products, and technology for evaluating a wide range of wood products, including standing trees, logs,...

Developing advanced building materials with both excellent thermal insulating and optical properties to replace common glass (thermal conductivity of ∼1 W m−1 K−1) is highly desirable for energy-efficient applications. The recent development of transparent wood suggests a promising building material with many advantages, including high optical transmittance, tunable optical haze, and excellent thermal insulation. However, previous transparent wood materials generally have a high haze (typically greater than 40%), which is a major obstacle for their practical application in the replacement...

Housing prices have generally performed better than economies in most countries in the UNECE region. Economic projections and house-price analysis can provide insights into the housing construction, sales and remodelling markets and subsequently into wood product demand. The Bank of International Settlements (BIS) reported that residential housing prices increased by 1.9% globally in 2018, year-onyear, and by 2.2% in the euro area, 2.0% in the US and 1.0% in the Russian Federation. Canadian house prices retreated, however, by 0.06%. According to BIS, real residential prices (adjusted for...

This paper numerically models the behavior of double-shear, single-bolted joints in wood-steel structures when subjected to very large deformations and compares results with test information. A three-dimensional finite-element model is developed of the main Douglas-fir wood member, steel side plates, bolt, washers, and nut. The model accounts for friction, bolt clearance, progressive damage in the wood, nonlinear and inelastic behavior in the steel bolts and side plates, and complete (linear and nonlinear) compressive constitutive response parallel to the grain in the wood. Hashin’s 3-D...