Abstract The construction sector aims to decrease greenhouse gas (GHG) emissions and increase circular use of construction materials. Many nonrenewable construction materials could be recycled more efficiently or replaced with renewable materials, such as wood. Cascading is the sequential use of wood in multiple material applications before incineration. This study estimated how much increased recycling and cascade use of wood could decrease GHG emissions of a concrete building, a cross-laminated timber building, and a modular building based on the use of wood. Furthermore, the study assessed how the increased recycling and cascading would influence the substitution effects of wood construction, i.e., on the avoided fossil-based GHG emissions when preferring wood to nonrenewable alternatives. The GHG emissions of construction materials of the buildings decreased 30 to 35 percent with assumed recycling rates and cascading principles, with the relative decrease being largest for the concrete building. Notably, using wood ash as a cement replacement decreased the GHG emissions of the concrete building the most. The substitution effect of wood construction was slightly reduced because of cascading and recycling. This study considered only fossil-based GHG emissions, and changes in the forest carbon balance were excluded.

Abstract Greenhouse gas emissions have increased significantly, driven by rising energy consumption and global population growth. The manufacturing sector is a major contributor to these emissions, emphasizing the importance of assessing carbon footprints across various production stages, including transportation. This study conducted a comprehensive life-cycle assessment to evaluate the environmental impacts of manufacturing bamboo bicycles using a specialized bamboo bending technology. Unlike conventional bamboo bicycles with tubular frames, this innovative model features frames constructed from curved bamboo panels produced by a dedicated bending machine. The assessment adhered to the publicly available specification 2050 framework, with a cradle-to-gate system boundary. Data were collected on site and analyzed using eFootprint software. Results show that manufacturing bamboo bicycles generates approximately 163.93 kg of CO2 equivalent emissions, a 56.7 percent reduction compared with the 378.7 kg CO2 equivalent emissions of traditional aluminum-frame bicycles. This highlights the low-carbon advantages of bamboo bicycles. These findings underscore the potential of bamboo bicycles as a sustainable alternative, providing valuable insights for optimizing production processes and promoting environmentally conscious consumption.

Abstract In this study, the modulus of elasticity of red maple (Acer rubrum) veneer, a native species abundant in eastern North America, was evaluated. These veneer sheets were 3.5 mm thick by 304 mm wide by 2.44 m long. Over 500 specimens were visually graded and subjected to a nondestructive stress wave test to determine the dynamic modulus of elasticity (MOEd). Subsequently, 60 specimens were selected for tensile testing to measure the static modulus of elasticity (MOEs). The average MOEd was 19.10 GPa, while the MOEs obtained from tensile testing was 11.88 GPa. This tension-based MOE value was very close to the bending test value for red maple lumber reported in the wood handbook (11.31 GPa). A regression analysis was conducted to evaluate the effects of density and defects on MOE. The results showed that density has a greater effect on MOEd than defects. A correlation was also developed between MOEd and MOEs. The results showed that the MOEd was 60 percent higher than the MOEs, with a weak positive correlation (r = 0.40). The stress wave velocity, as affected by different factors such as density, defects, and fiber orientation, strongly correlated with MOEd.

Abstract The establishment of national nature reserves has led to the protection of ecosystem diversity. In the context of China’s ecological protection system, controversies have arisen over the guarantee of dwellers’ well-being from forestland. This study uses Wuyi Mountain National Park (WYMNP) in China as an example to discuss the balance between ecological conservation and forest community benefits from forest products. Based on a cross-sectional survey, a logit regression method was adopted to explore factors influencing the ability of forestland holders within WYMNP to make productive financing decisions for forest production without policy intervention. Additionally, the government’s integrated management strategy that accelerates positive social externalities was explored. The results reveal that: before the establishment of WYMNP, forestland holders in this region that operated in the nontimber forest product (NTFP) industry had more incentives to make proactive productive financing decisions on forest production; second, enterprise forestland holders were more motivated to expand their forest products operations than individual forestland holders; finally, after the establishment of WYMNP, the government departments conducted adaptive policies including redemption of forestland and classifying the extent to which production activities could be performed. The government provides a compromise solution that supplies long-running payments in core ecological conservation areas to secure dwellers’ livelihoods, while in regular control areas, the opportunity to operate the NTFP industry is finitely provided with regular monitoring. This strategy provides insight that holistic optimization for the development of forest communities and dwellers could be incorporated into the mechanisms for the management of national parks globally.

Abstract Nondestructive evaluation (NDE) is an effective technology that has been used for many decades to assess wood properties. However, NDE has not been well developed for in-service assessment of railroad ties of various wood species, grades, and boundary conditions. Acoustic velocity (AV) of railroad ties in free (on ballast) and fixed (packed with ballast and under static weight) boundary conditions was investigated herein. Overall, 60 new on-grade, 40 new off-grade, and 55 Grade-one (1) legacy ties were investigated. Ties were either oak/hickory or mixed hardwood. All ties were first measured in the free boundary condition and then packed with ballast, weighted, and measured in the fixed boundary condition. Ties were placed on ballast with approximately 10- to 11-cm (4- to 4.5-in.)-wide gaps between each. The AV that was measured after each tie was placed on the ballast (AVfree). Next, the ties were packed with ballast. Then a static weight, mimicking the load of rails, was placed on each tie and the AV was measured (AVfixed) with a Hitman HM220. All data were analyzed using three-way analysis of variance. The AV was higher for new on-grade versus new off-grade and legacy ties. The AV was higher for fixed versus free boundary condition. These results indicate that AV could be used to separate on-versus off-grade ties during production and that laboratory-scale AV technology could develop into an in-service technique.

Abstract Measuring energy usage in the forestry trade is a topic of great significance. In this article, we use the World Input–Output Database and the multiregional input–output model to establish an embodied energy competition network and assess the influence of global value chain (GVC) integration on competition. The results show that (1) the intensity of competition for embodied energy in forestry is higher for exports compared with imports. Additionally, the import competition network exhibits lower connectivity and overall efficiency. (2) The core regions of the competitive network are primarily found in Europe, Asia, and the Americas. The United States consistently maintains a competitive advantage. However, forestry policies have led to a decline in the status of the United States, (3) The hierarchical structure of export competition is more pronounced. When the weighting degree exceeds 200, this phenomenon becomes more pronounced. (4) From the perspective of GVC, positive embedding in the GVC is negatively correlated with import competition. Backward GVC embedding is positively correlated with import and export competition. On the basis of the above results, this article proposes that countries where backward embedding is the main method should actively participate in building appropriate export international associations, participating in international organizations, and building a relatively harmonious and stable export competition market, thereby helping to maintain economic development and energy environment management.

Abstract This research evaluated the mechanical and physical properties of three underutilized hardwood species according to visual lumber grades. Findings are discussed in relation to the requirements recommended such as density, modulus of rupture (MOR), and modulus of elasticity (MOE) for the manufacture of cross-laminated timber (CLT) industrial mats, which is a potential end use of low-valued hardwood species. Results showed that all species tested had an average MOE greater than that required for CLT lumber. Visual grading was an important component in strength determinations as evidenced by the correlation between MOE and MOR. All grades of red oak (Quercus rubra L.) had higher densities than those of southern yellow pine, which is the traditional wood used in manufacturing CLT industrial mats, with a density of 616 kg/m3 at 12 percent moisture; the average density of the red oak tested was 770 kg/m3 at 13.98 percent moisture. All grades of red oak also had MOE and MOR values that met the requirements for lumber used in the manufacture of CLT industrial mats. For sweetgum (Liquidambar styraciflua L.), all grades met the required values for MOE and MOR, but only Grades 3 and 4 met the required density. All grades of yellow poplar (Liriodendron tulipifera L.) met the required MOE and MOR, but none met the required density.

Abstract Bakelite Chemicals LLC has developed an innovative microscopy technique to view adhesives “in use.” The cornerstone of the method is based on sample preparation. Samples of a composite wood product are sanded to a highly polished surface using a progression of sandpaper grits from lowest to highest. This preparation technique differs significantly from historical preparation techniques, which rely on soaking or embedding samples followed by thin-section creation using a microtome. The wet preparation technique causes wood cells compressed during production of the composite to swell and change how the adhesive is seen within those cells. The addition of water to the sample can also move uncured adhesive around the bond line. These changes can significantly alter the interpretation of how the adhesive performs during the manufacturing process. The new preparation technique combined with standard fluorescence microscopy has provided a groundbreaking and accessible ability to understand how an adhesive responds to process changes in manufacturing. Improving the understanding of the dynamic relationship between the adhesive and manufacturing processes will be crucial in helping the wood products industry take advantage of the rapid improvements in processing technology.

Abstract The aim of this study is to evaluate the possibility of re-establishment of the Paulownia tomentosa (Thunb.) Steud. forestry and wood industry for sustainable wood production in Japan. Bending properties were preliminarily investigated for dimension lumber (2 by 4, 38 by 89 mm in transverse section) and small-clear specimens of this species. The severe slope of grain in lumber reduced the modulus of rupture (MOR) and disturbed the relationship between the modulus of elasticity (MOE) and MOR. Preliminary studies determined a 5 percent lower tolerance limit with a 75 percent confidence level in MOR of lumber was 12.1 MPa. The value exceeded the characteristic value of MOR of 2 by 4 lumber in structural grade Western redcedar (Thuja plicata).

Abstract The integrity of melamine formaldehyde bonds in prototype cross-laminated timber (CLT) specimens was tested as part of a project on utilization of ponderosa pine (Pinus ponderosa) from forest restoration programs in the western United States. Bond integrity tests, block shear, and cyclic delamination are prescribed by ANSI/APA PRG-320 (ANSI/APA 2019) and ANSI 405 (ANSI 2018) to qualify new products. Of these, the cyclic delamination criterion is particularly challenging for layups developed in research labs and pilot plants. Delamination is often blamed on poor compatibility between adhesive and wood species, clamping pressure, or distribution of adhesive, neglecting other potential factors. One of the study objectives was to separate the effect of adhesive compatibility from other potential factors affecting bond integrity in CLT. Bonding integrity tests were conducted on prototype specimens bonded with melamine formaldehyde adhesive. Three types of specimens were studied: (1) specimens harvested from panels fabricated in an industrial CLT plant, (2) specimens harvested from panels fabricated in a pilot-line, and (3) short blocks cross-laminated from 102 by 102-mm sections. The short blocks included sections with juvenile wood and blue stain on bonded surfaces. All samples passed the PRG-320 block shear criteria. All short blocks passed the delamination criterion, demonstrating sufficient adhesive compatibility with the surfaces regardless of heavy presence of blue stain and juvenile wood. Specimens harvested from panels did not meet the delamination criterion. Delaminations developed near preexisting interlaminar gaps observed in prototype panels, which may be related to thickness variation or to inconsistent clamping pressure.