Simply substituting wood for conventional building materials could provide almost a tenth of the global carbon emission reductions needed to meet 2030 goals. However, while structural light-frame wood products are the go-to building material in the United States for low-rise residential construction, capturing over 90 percent of the market, any kind of wood-frame construction at the time under examination was limited to 5 stories and 85 feet in height. These story and height limitations dated back decades and prevented the design and construction of larger and taller buildings. In 2014, the American Wood Council (AWC) began developing a plan to expand these limits, but recognized it would require the International Building Code, the predominant model code adopted in most local and state jurisdictions in the United States, to embrace a new type of construction: fire-resistance-rated tall mass timber.Abstract
Commercial medium-density fiberboard (MDF) products, specifically manufactured for water resistance, were evaluated over 8 days under three water exposure regimes: 90 percent relative humidity, one-sided water spray, and one-sided wet pad. A three-cycle wet-pad and drying exposure test was also performed. Rate of swelling, extent of swelling, and irreversible thickness swelling were determined. Acetylated MDF (AMDF) had the best overall performance, followed by steam-injection pressed MDF (SMDF) and polymeric methylene-diphenyl-diisocyanate–bonded moisture-resistant MDF. The fastest rate of thickness swell and linear expansion occurred with exposure to one-sided water spray and the slowest with 90 percent relative humidity exposure. While AMDF was clearly superior after 24-hour exposure, the other MDF products were nearly identical. Significant difference in thickness swell and water absorption between moisture-resistant MDF and SMDF developed after 24 hours. Regardless of the method of water exposure, the trend of best to worst MDF performance was the same.Abstract
Mass ply panels (MPP), a relatively new mass timber product, has been utilized in several construction projects as diaphragm and wall panels. Connection for MPP is a crucial structural component that requires a better understanding. This article presents an experimental investigation into elevated temperature exposure–driven property degradation of MPP nailed connections, which is important for both the design of new structures in terms of fire resistance and the rehabilitation of structures partially damaged by fire. One control group and 32 exposure groups, which were combinations of eight elevated temperatures and four exposure durations, were investigated. The failure modes and yield strength of the nailed connection were analyzed as a function of elevated temperature and exposure time and compared with the prediction from the National Design Specification and existing literature. The results show a decrease of up to 45 percent in initial stiffness and ultimate load; meanwhile, there was no statistical evidence for the change in yield load in the majority of testing groups. Two analytical models, namely, multilinear regression and first-order kinetics model, were proposed to model the degradation of initial stiffness and ultimate strength. The kinetics model provided a better prediction and suggested that the initial stiffness and ultimate strength of the nail connection degraded over time at rates depending on the exposure temperature.Abstract
Forest products and timber harvesting businesses were severely affected by the COVID-19 pandemic. This article describes how forest products companies used Paycheck Protection Program (PPP) loans to keep over 487,000 workers in the forest industry on payroll through the pandemic. This article also summarizes the Pandemic Assistance for Timber Harvesters and Haulers (PATHH) program, payments provided to timber harvesting and hauling businesses that experienced losses in revenue in 2020. Timber harvesting and hauling companies that received a PATHH payment reported US$1.27 trillion in total revenue lost between 2019 and 2020 because of the COVID-19 pandemic.Abstract
As a primitive furniture with the longest history in China, the screen (pingfeng) originated in the western Zhou Dynasty and went through the Han and Tang dynasties, the Five Dynasties, the Song Dynasty, and the Ming and Qing dynasties and is still being used to date. This paper aims to explore the modern aesthetics contained in the traditional screen line and measure the contribution of some linear elements to the overall modern characteristics of the screen. By adopting the method of Kansei engineering, quantitative research is carried out on the Kansei image and the linear patterns of the traditional Chinese screens. The results show that the factors affecting the modern aesthetics of the screen have three linear elements: the top section (pingmao), the upright brackets (zhanya), and the base (dunzuo), with the top section and the base having the greatest influence on the “modern” kansei image of the screen. On the basis of these linear features, the style of the screen can be determined, and the quantitative data can provide reference for the design of modern screens.Abstract
Employment in the US logging industry has been declining over the past few decades and fell to a 20-year low following the 2008 economic recession. This study investigates the drivers of employment in the US logging industry from 2007 to 2017, using a directed acyclic graph (DAG). This approach is applied for the first time to disclose the contemporaneous causal relations among employment, wages, mechanization, production level, and product prices in the logging industry. Forecast error variance decomposition (VD) is further used to examine the long-run dynamic relationships between these variables. The results show that the product price directly affects employment and indirectly promotes employment through wages. The results of VD show that mechanization has an increasing long-term effect on employment.Abstract
The interest in softwood-based cross-laminated timber (CLT) production has in turn generated a great deal of interest in producing CLT from hardwood species. This prospect of a new market for hardwood lumber is a significant driver behind efforts to gain certification of hardwoods within American Panel Association (APA) PRG 320, Standard for Performance-Rated Cross-Laminated Timber. However, a number of challenges present significant hurdles for gaining acceptance of hardwoods in CLT manufacturing. These include differences in how softwoods and hardwoods are produced and marketed (e.g., structural lumber markets [softwoods] vs. appearance-grade markets [hardwoods]), lumber grading differences, available sizes of hardwood lumber, drying differences between hardwoods and softwoods, and gluing particularities with hardwoods. This paper identifies the various issues involved with introducing hardwoods into a softwood-dominated market and what it will take to be competitive within the overall CLT market.Abstract
By the Forest Products Society Investment Management Committee (IMC) Justin Price- FPS President Terry Liles- FPS Former President Bob Breyer- FPS President Elect Matt Holt- FPS Vice President Chris Butts- FPS Executive Vice President Henry Quesada- SWST President Victoria Herian, SWST Executive Director In accordance with Peter Koch’s letter of Intent a joint FPS and SWST Committee was formed to oversee the management of the Peter and Doris Koch Endowment Funds in 2017. Peter Koch indicated that the purpose of the Oversight Committee is “to audit the previous year’s actions regarding the three endowment funds” and “rule annuallyExecutive Summary