European Journal of Wood and Wood Products最新文献

Based on the geometrical characteristics of thick-strip engineered bamboo panels, the experimental methods in accordance with current testing standards are proposed in this research. The strength values of structural used engineered bamboo panels under various loading conditions are reported in terms of tension, compression, bending, and shear. The average stress-displacement curves of panels with different thicknesses are given and compared in this study. The k-sample Anderson–Darling (ADK) test was used to statistically analyze the effect of thickness on three batches of strength values, and the test results indicated that the three groups of data were drawn from different populations, demonstrating that the thickness significantly affects the material properties of bamboo panels. Using the original test data obtained, strength values and the corresponding coefficient of variation (COV) were calculated and compared. Probability plots of the strength values indicate that the distribution can be described as a normal distribution variable with a 95% level of confidence. Based on the test information obtained from different small specimen numbers, ranging from 5 to 60, the characteristic strength values of the structural used bamboo panels are estimated according to the design-by-test approach. Additionally, the compressive performance and corresponding characteristic load-bearing capacity of cross-laminated-bamboo (CLB) based on the engineered bamboo boards are also investigated in this research.

Currently, wood dyeing technology plays an important role in its enhancing aesthetics and market competitiveness. However, still facing the dual challenges of insufficient color fastness of dyeing and environmental pollution caused by dye wastes generated during the dyeing process. Herein, an efficient and environmentally friendly dyeing method was proposed to improve color fastness utilizing chemisorption and electrostatic adsorption in low concentration dyeing solution. The chemical modification of Ayous wood using 2,3-epoxypropyltrimethylammonium chloride was carried out by introducing the cationic groups to reduce the dyeing resistance and increase the binding force of dye molecules on the wood. Kinetic and thermodynamic analyses revealed that the adsorption behavior between cation-modified bleached wood (CBW) and acid dyes adheres to the quasi second-order kinetic model (R² = 0.98) and Freundlich isothermal model (R² = 0.91), suggesting an adsorption process in which chemical adsorption dominated. Therefore, there was a significant increase in color fastness. Compared to the traditional dyeing method, the quantity of dyes consumed in this method can be reduced by 40%, significantly diminishing the environmental load of dyeing waste liquid. This study offers an efficient and environmentally friendly modification strategy for wood dyeing, highlighting a potential of CBW for practical applications.

The aim of this study was to develop a new type of micronized copper-based wood preservative that would improve the problem of easy leaching of copper ions associated with other copper-containing wood preservatives. Micronized copper sulfide (CuS) is simple to prepare, provides good anti-fungal protection, and is leaching resistant. The stability of micronized CuS, the extent of leaching of copper ions from wood, and the effect before and after deliberate leaching on antifungal efficacy were investigated. When the retention of CuS was 4.8 kg/m³, the wood mass loss rate after infection with Trametes versicolor, Gloeophyllum trabeum, or Neolentinus lepideus fungi was < 10%, and when the retention was 2.16 kg/m³, only 1.87% was leached. Then, micronized copper sulfide azole (CuSA) was developed to provide comprehensive protection against wood decay fungi, especially copper-resistant fungus Rhodonia placenta. Preservative effects and changes in the chemical and micromechanical properties of the treated wood were investigated. When the retention of CuSA was 1.92 kg/m³, the mass loss from leached wood blocks after exposure to Rhodonia placenta fungi was only 3.51%. There were a few significant effects on the chemical and micromechanical properties of treated wood. This study provides a new approach to the design and preparation of effective wood preservatives with less leaching.

The branches of deciduous trees are optimised by nature to allow continuous adaptation and response to changing environmental conditions. As a result, the morphology and internal structure of the wood branches are often more variable than in the stem. Quantitatively, branches and stem tops represent 20–50% of the volume of the above-ground biomass of deciduous trees, which is currently under-utilized and mainly burned. To enable a higher-value application as a safe construction material, a comprehensive technological profile of branch wood is a prerequisite. Therefore, we performed single-blow impact pendulum tests in tangential wood direction on branch and stem wood samples of beech, oak, and poplar to investigate their relationship with wood density, macrostructural properties, fibre properties, and microfibril orientation of selected samples. Our results showed that the significant differences in mean impact bending strength between branch and stem for all species could not be explained by wood density. However, branch and stem wood with higher toughness are generally associated with longer fibres. Overall, branches showed higher MFA (microfibril angle) and lower fibre length compared to stems. We found that higher toughness in selected beech samples was associated with higher density and lower MFA. While oak also had a lower MFA, poplar had a higher MFA in high-toughness samples. Our empirical results provide insights into the species-specific structure-property relationships of hardwood branches, improving the understanding of their properties and variability, and potentially informing their use in structural applications.

This study aimed to analyze an optimal utilization system to maximize the economic value of domestic oak (Quercus Mongolica Fisch. ex Ledeb.) log in the value chain to expand the use of wood resources and by-products. Initially, visits were made to medium-density fiberboard (MDF) factories and other companies that utilize domestic oaks to assess the size and quality of products at each stage of use, as well as the status of by-product collection and sales. Furthermore, potential alternatives to wood processing or by-product utilization were explored to facilitate the transition to a bio-economical system. Subsequently, an analysis was conducted to identify the types and quantities of wood products that could be derived from oak and evaluate the economic and environmental benefits of usage scenarios if they were adopted as new alternative resources. Finally, based on the study findings, suggestions are made for future enhancements in the domestic wood distribution process and by-product utilization system, with a focus on the application of a forest-based bioeconomy. The production of flooring boards using high-frequency vacuum drying has been highlighted as a means to increase the value-added and extend the carbon storage period by promoting its use as a long-lived product. Therefore, in addition to endeavors to enhance the price competitiveness of domestic wood products and explore ways to leverage high value-added by-products, there is a need to invest in advancing technology to maximize the value-added potential of domestic wood products.

The European Union pushes for a higher share of wood-based materials in the building sector. Consequently, making sufficient volumes of high-quality wood available is a major concern. Climate-driven forest conversion leads to an increasing share of hardwood trees in Central European forests. The use of hardwood species is currently uncommon in the building sector as hardwood species are not sufficiently covered by European standards for timber structures. In addition to this, lower material yields and increased tool wear are common in hardwood processing. Furthermore, grading hardwood species comes with major difficulties, leading to even lower yields and an assignment to strength classes worth improving, as only parts of the material can properly be assigned to strength classes. To substitute the board-based grading approach we produced a semi-finished product, “strip-like lamination” (SLL). Preselected, low-grade sawn hardwood from European beech (Fagus sylvatica) and oak (Quercus spp.) was used as raw material for the SLLs. Each lamination consists of multiple “strips”, stemming from different hardwood boards, mitigating the strength-limiting effect of various wood characteristics in these SLLs. This work provides the first comprehensive mechanical performance profile for SLLs from beech and oak including the finger joint performance. Furthermore, we show the extent of the desired homogenization of the raw material through non-destructive testing. The mechanical properties of beech SLLs exceed the requirements for European softwood strength classes. The results show great potential for SLLs in structural applications. SLLs should complement strength-graded structural timber in structural glued wood products, like glued laminated timber (GLT) and cross-laminated timber (CLT).

With the rapid development of the economy and society, problems such as high resource consumption and serious environmental pollution in traditional reinforced concrete buildings are becoming increasingly prominent. Bamboo scrimber is an effective substitute for green building materials, but there are some problems such as susceptibility to mildew and poor flame retardancy, which limit its application in the building industry. In this study, the alkaline pretreatment process was used to remove some nutrients from bamboo to improve mildew resistance, and phytic acid and magnesium hydroxide were loaded on the surface of the bamboo bundle to enhance the flame retardancy. The results showed that phytic acid and magnesium hydroxide could be effectively loaded on the surface of bamboo bundles, and the mechanical strength, mildew resistance, and flame retardancy of modified bamboo scrimber (M10-PB) have been effectively improved. Compared with unmodified bamboo scrimber, the flexural strength and flexural modulus of M10-PB increased by 33.72% and 36.61% to 155.26 MPa and 14.59 GPa, respectively; the mold infection rate has decreased from 100% at 5 d to below 20% at 28 d; the limiting oxygen index of M10-PB bamboo scrimber increased by 13.2%, and the total smoke emission decreased by 54.4%. This method can effectively improve the mildew resistance, flame retardancy and smoke suppression of bamboo scrimber while maintaining high mechanical strength, which helps to promote the application of bamboo in the construction field.

Drones facilitate the monitoring of large structures through feature extraction from point clouds generated through Structure-from-Motion photogrammetry. In the present study, we determined the deformation of a structural timber strip subjected to simultaneous bending and torsion. Three cameras were used. Two of them are pre-installed on the UAVs utilized, and the third is a consumer-grade Canon camera. All three were configured in flight mode. The geometry of the timber strip was generated through photogrammetry from the photos taken with each camera at a height of 1.5 m. The results were compared with the reference geometry, which was also created using the Canon camera on the ground at an average distance of 0.92 m. This reference geometry was previously validated in a preparatory project using extensometers with 1-µm precision. A Python-based algorithm was developed to automatically extract the position of the centroid and the rotation of each cross-sectional segment of the strip from UAV-based photogrammetric point clouds. Deformations measured by each of the three devices and the new algorithm are compared with actual deformation. The accuracy in measuring displacement and rotation of the centroid of strip cross-sections ranged between − 0.05 and 0.09 mm and between 0.00° and 0.24°, respectively.

This paper presents an investigation to check the feasibility of reinforcing laminated bamboo columns through the application of glass fiber reinforced polymer (GFRP) composites, with particular emphasis on examining the influence of slenderness ratio on the performance of GFRP reinforced columns. A comprehensive experimental program was conducted involving eighteen full-scale columns, which were categorized into six distinct slenderness groups. External GFRP wrapping was employed to enhance compression strength, as well as to restrain the outward local buckling deformation of the laminated bamboo column. Experimental observations revealed both compression and buckling failure modes. The results demonstrated that the implementation of GFRP reinforcement with a minimal volume fraction significantly enhanced both the load-carrying capacity and deformation ability of the laminated bamboo columns. A consistent inverse relationship was observed between the slenderness ratio and the ultimate load-carrying capacity of the specimens. To further validate and extend the experimental findings, a methodology for modeling the column specimens was developed using ABAQUS software, incorporating nonlinear analysis to simulate the behavior. The numerical simulations exhibited strong correlation with experimental results, thereby confirming the reliability and effectiveness of the proposed methods for potential similar engineering applications.