Search Results (95)

Canadian sawmills commonly use chipper-canters to process softwood logs into squared lumber and wood chips for pulp mills. However, the declining demand for newsprint and print paper has led to an oversupply of wood chips, resulting in economic losses and environmental concerns. To address this issue, a strander-canter capable of producing both softwood cants and strands for oriented strand board (OSB) presents a promising alternative. This study evaluates the feasibility of using jack pine strands generated by a novel strander-canter equipped with a cutterhead for OSB strand production. Strands were generated from frozen and unfrozen logs under varying cutting parameters and incorporated in the core layer of the panels. Industrial aspen strands were used for the surface layers. OSB panels were assessed for mechanical and physical properties following the CSA O325:21 standard. Strand size distribution and vertical density profiles were also analyzed. The results indicated that panels made from jack pine strands demonstrated bending and internal bond properties that were either comparable to or superior to those of the control panels. However, including jack pine strands in the core layer increased the thickness swelling of the panels. Full article

Understanding forest-cover change and its drivers is vital for global forest management and policy development. This study analyzed perceptions of historical drivers behind land-use/land-cover change (LULCC) and forest change in gazetted forests from 1966 to 2022 to evaluate the impact of human activities around the gazetted forest reserves, comparing three forests in Nasarawa State, North Central Nigeria. Data were collected through questionnaires, interviews, and focus group discussions. Three gazetted forests (Doma, Risha, and Odu) were sampled to represent the three geopolitical zones of the state. SPSS IBM version 29, NVivo 1.7, and Python 3 were used for data analyses to generate statistics and identify coherent themes across the forests. Results show that changes were perceived to be triggered by sixteen drivers (direct and indirect) related to social, economic, environmental, policy/institutional, and technological elements. Agricultural expansion, lumbering, and charcoal production were the most reported direct drivers, while population growth, poverty, and government policies were the most perceived indirect drivers. The results showed variations in human activities across forest sites. For example, agricultural expansion, lumbering, and grazing were more widespread, while construction and settlement activities differed between forests. The Risha forest community saw agriculture expansion ahead of other drivers, Doma forest people saw population growth above other drivers, and the Odu forest community saw lumbering aiding other drivers that led to change. Implementation of policies focusing on these key drivers must match local perceptions and priorities to engage people in forest conservation. These efforts could ensure effective forest protection that is vital for achieving global biodiversity and climate targets and safeguarding local livelihoods. The specific drivers of changes in each forest need to be targeted in conservation efforts. Full article

The relationship between silvicultural strategies, manifested in the thinning method and rotation age on sites with different water supply, and the mechanical properties of engineered wood products plywood and laminated veneer lumber has been analyzed. Sample logs from five German sites of Norway spruce (Picea abies (L.) Karst.) and Douglas fir (Pseudotsuga menziesii (M.) Franco) have been rotary-peeled and processed into boards with a phenol–resorcinol–formaldehyde adhesive to evaluate their performance under flexural, tensile, and compressive loads. Satisfactory coefficients of determination were reached for Norway spruce in regard to the silvicultural framework and the tree characteristics of slenderness and crown base height. Douglas fir products did not achieve comparable determination due to high variance within boards and stands but did achieve significantly better mechanical properties. Norway spruce was observed to be more responsive to thinning measures, while the effect of different thinning regimes was not evident for Douglas fir. The on-site evaluation of Douglas fir stands for veneer product quality based on silvicultural parameters and tree characteristics was shown to be inconclusive, with its naturally higher wood density being the decisive constant. Full article

Due to the development of wooden construction as an ecological alternative to brick construction with a high carbon footprint, there is increasing interest in materials such as plywood and LVL (Laminated Veneer Lumber). These engineered wood products have many advantages compared to wood, such as a more uniform distribution of bending, shear, tensile, and compressive strength. However, they require improvements in fire and biological resistance. The flammability of wood and wood composites is a challenge that will allow these materials to stand out as structural or finishing materials. During combustion, toxic gases may be released, which can be harmful to people and the environment. Therefore, it is crucial to clarify whether fire-resistant wood materials are truly resistant to fire and non-toxic in fire conditions. On the other hand, flame retardants should not reduce the mechanical parameters of panels. This work analyses the current requirements (standards) regarding plywood intended for construction and the existing flame retardants for plywood and LVL based on the latest reports in the literature. We then propose an original method for evaluating future chemicals. Additionally, methods for assessing the flame retardancy of plywood and LVL based on the latest reports in the literature are described, and an original method for assessing flame retardancy methods is proposed. Full article

The construction sector’s increasing eco-consciousness is driving the need for higher-performance wood-based engineered products from underutilized timber resources, such as small-diameter trees from hazardous fuel treatments of our forests. Strand-based products, including oriented strand board (OSB) and lumber (OSL), are widely used. However, hot-pressing during their manufacturing generates approximately 10% waste, which includes a substantial amount of resinated strands that are landfilled. The huge potential of using strand-based products has led to many studies and growing interest in strand-based three-dimensional sandwich panels that can be used as wall, floor, or roofing panels. As the market grows, understanding the recyclability of these resinated strands becomes crucial. This study investigates the feasibility of using re-resinated waste strands that were collected during lab-scale production of strand-based panels. Results demonstrate significant improvements in dimensional stability, mechanical properties, and fire resistance. Specifically, recycling increased internal bond strength, flexural strength, time to ignition, time to flameout, mass loss, and time to peak heat release rate by 107%, 44%, 58%, 35%, 51%, and 27%, respectively, and helped decrease water absorption and thickness swell by 51% and 58%, respectively. Full article

The challenges highlighted at the 29th Conference of the Parties (COP29) emphasize the importance of using renewable resources in the architecture, engineering, and construction (AEC) industry. The building and construction sector is a major contributor to environmental pollution, with most emissions stemming from the extraction, transportation, production, and disposal of construction materials. As a result, developing renewable building materials is essential. In the past decade, bamboo has gained significant attention from researchers due to its strength, sustainability, high yield, and rapid growth. Bamboo in its original form has been used in construction for centuries, and recent innovations have led to the creation of engineered bamboo materials designed for more versatile applications. Researchers have been focused on understanding the physical and mechanical properties of engineered bamboo to assess its potential as a sustainable alternative to traditional building materials. However, modern practitioners are still unfamiliar with engineered bamboo materials, their types, and where they can be used. This article highlights the most widely researched engineered bamboo materials that have been used in the construction of small architectural forms and bigger structures. It provides an overview of common engineered bamboo building materials, namely laminated bamboo lumber, laminated bamboo sheets, parallel strand bamboo, bamboo mat boards, and bamboo particleboards, and their manufacturing processes and applications, offering valuable information for current practitioners and future research. Full article

This case study conducted a cradle-to-gate life cycle assessment (LCA) on the production of hardwood lumber in New Brunswick, Canada, evaluating the environmental impacts from raw material extraction to the point where lumber exited the mill as rough green lumber, the primary input for manufacturing pallets and railway ties. Data on annual production, material flow, and energy use for harvesting and sawmilling were gathered through survey questionnaires and on-site visits. The life cycle inventory (LCI) was developed in SimaPro software, the life cycle impact assessment (LCIA) was conducted using the North American TRACI method to quantify impact categories, and the cumulative energy demand (CED) method was employed to analyze the total energy consumption. It was found that rough green hardwood lumber production emitted approximately 41 kg CO₂⁻eq/m³ (excluding biogenic carbon storage), with manufacturing accounting for 42% of total emissions and consuming 736 MJ/m³ of total energy, 98% of which came from non-renewable sources. The carbon stored in lumber was 975 CO₂ eq/m³, 24 times greater than its cradle-to-gate emissions, highlighting its significant environmental benefit. Future research will aim to conduct a cradle-to-grave LCA on hardwood production by including drying and planing and increase the number of sawmill samples. Full article

This study addressed multi-product optimization in Cedrelinga cateniformis plantations in the Peruvian Amazon, aiming to maximize volumetric yields of logs and sawn lumber. Data from seven plantations of different ages and types, established on degraded land, were analyzed by using ten stem profile models to predict taper and optimize wood use. In addition, the structure of each plantation was evaluated using diameter distributions and height–diameter ratios; log and sawn timber production was optimized using SigmaE 2.0 software. The Garay model proved most effective, providing high predictive accuracy (adjusted R² values up to 0.963) and biological realism. Marked differences in volumetric yield were observed between plantations: older and more widely spaced plantations produced higher timber volumes. Logs of optimal length (1.83–3.05 m) and larger dimension wood (e.g., 25.40 × 5.08 cm) were identified as key contributors to maximizing volumetric yields. The highest yields were observed in mature plantations, in which the total log volume reached 508.1 m³ha⁻¹ and the sawn lumber volume 333.6 m³ha⁻¹. The findings demonstrate the power of data-driven decision-making in the timber industry. By combining precise modeling and optimization techniques, we developed a framework that enables sawmill operators to maximize log and lumber yields. The insights gained from this research can be used to improve operational efficiency and reduce waste, ultimately leading to increased profitability. These practices promote support for smallholders and the forestry industry while contributing to the long-term development of the Peruvian Amazon. Full article

Forecasting sales trends is a valuable activity for companies of all types and sizes, as it enables more efficient decision making to avoid unnecessary expenses from excess inventory or, conversely, losses due to insufficient inventory to meet demand. In this paper, we designed a personalized cost function to reduce economic losses caused by the excessive acquisition of products or derived from their scarcity when needed. Moreover, we designed an LSTM network integrated with Glorot and Orthogonal initializers and dropout to forecast sales trends in a lumber mill in Tamaulipas, Mexico. To generalize and appropriately forecast the sales of the lumber mill products, we optimized the LSTM network’s hyperparameters through a genetic algorithm, which was essential to explore the solution space. We evaluated our proposal in instances obtained from the historical sales of the five main products sold by the lumber mill. According to the results, we concluded that for our case study the proposed function cost and the hyperparameters optimization allowed the LSTM to forecast the direction and trend of the lumber mill’s product sales despite the variability of the products. Full article

Solid wood is renowned as a superior material for construction and furniture applications. However, characteristics such as dead knots, live knots, piths, and cracks are easily formed during timber’s growth and processing stages. These features and defects significantly undermine the mechanical characteristics of sawn timber, rendering it unsuitable for specific applications. This study introduces BDCS-YOLO (Bilateral Defect Cutting Strategy based on You Only Look Once), an artificial intelligence bilateral sawing strategy to advance the automation of timber processing. Grounded on a dual-sided image acquisition platform, BDCS-YOLO achieves a commendable mean average feature detection precision of 0.94 when evaluated on a meticulously curated dataset comprising 450 images. Furthermore, a dual-side processing optimization module is deployed to enhance the accuracy of defect detection bounding boxes and establish refined processing coordinates. This innovative approach yields a notable 12.3% increase in the volume yield of sawn timber compared to present production, signifying a substantial leap toward efficiently utilizing solid wood resources in the lumber processing industry. Full article

Structural lumber is designed to meet the technical standards that ensure safety, cost-effectiveness, and sustainability. However, some tree species face limitations in their growth, which restricts their widespread use. An example of this is Nothofagus alpina, which has excellent mechanical properties but is not utilized much due to the challenges in extracting its timber and poor utilization, mainly because of the length of the wood. There is little information concerned with the uses and better management of small pieces using Nothofagus species, but it is still insufficient. This study investigates the adhesion performance of green-glued finger joints with varying wood ring orientations and moisture contents ranging from 21% to 25% using Nothofagus alpina. The primary aim is to assess how ring orientation and wet timber affect the green gluing process for creating larger wood pieces than sawn wood. The resulting products could meet the standards for wood serviceability number three for native Chilean wood. The findings indicate that finger joint performance improves with higher timber moisture levels. However, the orientation of the wood fibers did not significantly affect the performance under the tested conditions. It is important to note that this effect may become more significant near the fiber saturation point. These findings emphasize the need for a detailed protocol on the green gluing technique for Nothofagus alpina and the associated drying and surface processes in finger joint construction. Full article

Lightweight engineered trusses support sustainable construction with the benefits of mass production and fast construction at lower costs. However, the truss system has raised concerns due to premature failure in fire conditions. This study investigates the effect of a thin soot layer on the surface of the gusset plate and the teeth of the gusset plate on the temperature development within lightweight wood specimens in fire conditions. A 10 cm long, 8.9 cm wide, and 3.8 cm thick dimensional lumber (often called 2 by 4) partially covered by a gusset plate was exposed to a constant incident radiant heat flux. A total of 12 experiments were conducted with four different configurations, bare gusset plates with and without teeth and soot-coated gusset plates with and without teeth, at three different external radiative heat fluxes of 10, 15, and 20 kW/m². The exposure durations were set to be 60, 40, and 30 min, respectively, to allow the total applied amount of radiant energy for each specimen to be identical. Three thermocouples were installed at a depth of 13 mm from the exposed wooden surface: two beneath the gusset plate and one below the uncovered wooden surface, and an additional thermocouple was between the gusset plate and the wood surface. The obtained temperature data showed that soot-coated gusset plates absorb significantly more radiation and record higher temperatures within the specimens than the specimens with the bare gusset plates. It was also found that the bare gusset plate works as a protective layer for the wood at 20 kW/m², but not at 10 and 15 kW/m². The teeth certainly contributed to heat transfer increasing the temperatures within the wood higher than those without teeth, but the effect was only meaningful for the soot-covered specimens. Connection strength was also qualitatively analyzed and it was discovered that the bare specimen retained a strong connection between the gusset plate and wood. In contrast, the soot-coated specimen was easily removed by hand, even when exposed to the same heat flux. Applying these results to a realistic scenario, this loss in connection strength could result in truss failure and structural collapse, which may result in injury to or even death of the responding firefighters. Additional gusset plate protection measures may be necessary to prolong the connection strength and prevent structural collapse. Full article

Plantations, typically involving the cultivation of fast-growing trees like southern yellow pine, offer avenues to enhance sustainability and manage limited resources more effectively. However, fast-growing trees suffer from low mechanical properties due to less dense wood. Densification and the development of engineered wood products represent approaches to developing high-performance products from fast-growing tree species. In this study, the correlation between the densification levels and mechanical properties of a fast-growing species, loblolly pine (Pinus taeda L.), was established to improve resource utilization. Wood specimens were densified at three compression ratios: 16.67%, 33.33%, and 50.00%. The impact of densification levels on bending strength, bending stiffness, shear strength, and hardness was studied. The findings highlighted the positive impact of densification on structural integrity, as bending stiffness consistently improved, eventually reaching a 42% enhancement at a compression ratio of 50.00%. However, bending strength showed an initial increasing trend but reached a plateau at higher densification levels. Densification levels showed minimal changes in shear strength parallel to the grain. Notably, densification significantly enhanced hardness properties, particularly on the tangential surface, where a fourfold increase was observed at a 50% compression ratio. Overall, these findings reveal the relation between the compression ratio and the mechanical properties of lumber and are beneficial for utilizing lower-quality wood species in construction and engineering applications. Full article

Trembling aspen (Populus tremuloides) is one of the major species within Populus, a predominant genus of hardwoods in North America. However, its utilization has been limited to pulp and paper or wood-based composite boards. This study aimed at evaluating the major physical and mechanical properties of trembling aspen lumber, with an ultimate objective of using this species to produce engineered wood products (EWPs). The testing materials consisted of 2 × 4 (38 mm × 89 mm) trembling aspen lumber pieces in lengths of 8, 10, and 12 feet (2.44, 3.05, and 3.66 m) with two visual grades, select structural (SS) and No. 2. Machine Stress-Rated (MSR), and longitudinal stress wave (LSW), edgewise third-point bending (EWB), and axial tension tests were conducted on the lumber. It was found that, (1) by increasing the maximum knot size by a half-inch from one-quarter inch, the minimum modulus of elasticity (MOE) measured using the MSR, the mean, and the fifth-percentile ultimate tensile strength (UTS) decreased by about 8.8%, 20.1%, and 29.8%, respectively. (2) Approximately 44% of the trembling aspen lumber met the 1450f-1.3E grade for MSR lumber, and 62% qualified for the 1200f-1.2E grade. (3) There was a great potential for manufacturing cross-laminated timber (CLT) of grade E3, with a rejection rate of about 29%. (4) The mean UTS and MOE values of the SS-grade trembling aspen lumber were 22.88 MPa and 9519 MPa, respectively, being 25.5% and 11.3% lower than that of Spruce–Pine–Fir (S-P-F) lumber. The fifth-percentile UTS and MOE values were 11.57 MPa and 7404 MPa, respectively, marking a decrease of 13.3% and 1.5% compared to the S-P-F lumber. (5) The oven-dried specific gravity (SG) of the trembling aspen wood was 0.40, which was about 3.5% larger than the value provided in the Wood Handbook. Full article

Over-budgeting due to inflation is a common phenomenon in the construction industry of both developed and developing countries. Inflation, with time changes, leaves an adverse effect on the project budget. Hence, this study aims to focus on the construction price index (CPI) behavior and inspect its correlation with inflation in Thailand’s construction industry as there has not been much work performed. The prediction of CPI was made from 2024 to 2028, relying on the data set from 2000 to 2023. The relationship between inflation and CPI categories helps in prediction by considering inflation as the independent variable and CPI (All Commodities, Lumber and Wood Products, Cement, and Iron Products) as the dependent variable that was incorporated in EViews to perform automated ARIMA forecasting. The correlation results show that out of four CPI, only Iron Products showed a significant relationship with inflation. For All Commodities, Lumber, and Wood Products, the predicted values were fluctuating, while for Cement and Iron Products, a clear seasonal pattern was observed. This prediction gives a direction to construction industry practitioners to make necessary adjustments to their budget estimation before signing the contract to overcome cost overrun obstruction. Full article