Treesearch

A mass timber lateral force resisting system (LFRS) is proposed using a mass timber buckling restrained brace (TBRB) to improve the seismic resilience of mass timber buildings. To develop a resilient braced frame, it is essential to understand and quantify the behavior of the connections, including the possible failure modes and moment-rotation capacities. Cyclic and monotonic tests were conducted on six mass timber beam-column connections to study the response of a mass timber joint connected with slotted-in steel plates and mild steel dowels. The primary goal of the subassembly tests was...

Several material properties of wood are directionally dependent. Mechanical properties such as tension, compression, and bending strength vary greatly for the same piece of wood when tested parallel to the grain (longitudinally), perpendicular to the grain and parallel to the annual rings (tangentially), or perpendicular to both the grain and rings (radially). For this reason, wood is often considered to be a cylindrically orthotropic anisotropic material. The orthotropy extends to dielectric properties of wood. However, in the presence of internal decay, the directional dependency of the...

Each year, agricultural residues such as stalks, husks, and pits/nutshells from food crop harvesting are available on a gigatonne scale worldwide. While biorefinery routes have been used convert agricultural residue carbohydrates into value-added products (e.g., bioethanol, biochemicals), the lignin, comprising 20–50% of the dry mass of agricultural residues, remains largely underutilized. Therefore, there is an urgent need to explore the utilization of agricultural biorefinery lignins for value-added products. In this review, we briefly introduce the origins of agricultural lignins,...

The efficacy of a spray-on combination formula containing the insecticides thiamethoxam and chlorantraniliprole was tested against subterranean termites using a covered ground proximity test. The test consisted of six treatments, five were chemical treatments and one was water control. Southern pine wood samples were treated with varying rates or treatment methods of the aforementioned insecticide combination, chlorantraniliprole alone, borate alone, or no chemical (water) treatment. Treated samples were installed at the Harrison Experimental Forest in Saucier, Mississippi using a modified...

Thermally modified wood (TMW) is a growing trend in North America in areas of low decay and insect pressure. Thermal modification improves dimensional stability, decreases moisture uptake, and results in a darkened color that resembles tropical hardwoods. More testing is needed in severe decay situations and in areas of high termite pressure to fully understand the boundaries of its material performance. Within the AWPA, the P9 subcommittee (non-biocidal wood protectants) has been working to develop test methodologies and appropriate use category designations for TMW materials. The Forest...

Moisture-selective polymer-based membranes can be a promising method for energy saving in drying systems of different industries that vent moisture vapor-rich air to the atmosphere, such as wood drying, biorefinery, food processing, and pharmaceutical industry. Developing a sustainable product with bio-based materials reduces the environmental impacts. This study assessed the techno-economic feasibility and life-cycle environmental impacts of producing a novel cellulose nanocrystal/polydimethylsiloxane hybrid moisture-selective membrane. The cradle-to-gate assessment was facilitated by...

Secondary plant cell walls are composed of carbohydrate and lignin polymers, and collectively represent a significant renewable resource. Leveraging these resources depends in part on a mechanistic understanding for diffusive processes within plant cell walls. Common wood protection treatments and biomass conversion processes to create biorefinery feedstocks feature ion or solvent diffusion within the cell wall. X-ray fluorescence microscopy experiments have determined that ionic diffusion rates are dependent on cell wall hydration as well as the ionic species through non-linear relationshi...

The purpose of this paper is to examine whether isothermal microcalorimetry can be used to determine the corrosion rates of metals embedded in wood. Metal fasteners were driven into dowels of wood treated with alkaline copper quaternary, a common wood preservative that increases the corrosiveness of wood. The dowels were stored in a nearly 100% relative humidity environment at 27°C for one year; throughout the exposure period, dowels were removed and the thermal power generated by the sample was measured in an isothermal calorimeter. Measurements over the 1-year exposure showed that the...

Cellulose nanofibrils (CNFs) were produced from bleached eucalyptus kraft pulp using microfluidization varying the number of passes through the microfluidizer. CNFs were processed into dry films to elucidate the effect of CNFs morphology on the physical, optical and barrier properties of the films. As the number of passes through the microfluidizer increased, the fibril diameter and degree of polymerization decreased. A higher number of passes produced CNFs with smaller diameter resulting in CNF films with smaller root mean surface (RMS) roughness, higher tensile strength and Young’s...

Is our logger population aging? What trends are we seeing in logging equipment? What business environment are loggers experiencing? What impact did the pandemic have on loggers? These are some of the questions we asked in the 2022 Loggers Survey. The results that we discuss come from loggers in Minnesota and Wisconsin. We asked our questions based on what they experienced during the previous year – 2021.