Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (162)

Search Parameters:
Keywords = wooden composites

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
26 pages, 449 KiB  
Review
The Science of Aging: Understanding Phenolic and Flavor Compounds and Their Influence on Alcoholic Beverages Aged with Alternative Woods
by Tainá Francisca Cordeiro de Souza, Bruna Melo Miranda, Julio Cesar Colivet Briceno, Joaquín Gómez-Estaca and Flávio Alves da Silva
Foods 2025, 14(15), 2739; https://doi.org/10.3390/foods14152739 - 5 Aug 2025
Abstract
Aging in wooden barrels is a proven technique that enhances the sensory complexity of alcoholic beverages by promoting the extraction of volatile and phenolic compounds. While oak has been traditionally used, there is a growing interest in exploring alternative wood species that can [...] Read more.
Aging in wooden barrels is a proven technique that enhances the sensory complexity of alcoholic beverages by promoting the extraction of volatile and phenolic compounds. While oak has been traditionally used, there is a growing interest in exploring alternative wood species that can impart distinct sensory characteristics and promote innovative maturation processes. This review examines the impact of alternative woods on the aging of beverages, such as wine, cachaça, tequila, and beer, focusing on their influence on aroma, flavor, color, and chemical composition. A bibliometric analysis highlights the increasing scientific attention toward wood diversification and emerging aging technologies, including ultrasound and micro-oxygenation, which accelerate maturation while preserving sensory complexity. The role of toasting techniques in modulating the release of phenolic and volatile compounds is also discussed, emphasizing their contribution to unique sensory profiles. Additionally, regulatory aspects and sustainability considerations are explored, suggesting that alternative woods can expand flavor possibilities while supporting environmentally sustainable practices. This review underscores the potential of non-traditional wood species to drive innovation in the aging of alcoholic beverages and provide new sensory experiences that align with evolving consumer preferences and market trends. Full article
(This article belongs to the Section Drinks and Liquid Nutrition)
22 pages, 8078 KiB  
Article
Experimental Testing of the Efficiency, Stability, and Compatibility of Fillers in the Conservation and Restoration of Water-Gilded Wooden Heritage
by María-Ángeles Carabal-Montagud, Laura Osete-Cortina, Ángel Vicente-Escuder and Celia Laguarda-Gómez
Appl. Sci. 2025, 15(15), 8276; https://doi.org/10.3390/app15158276 - 25 Jul 2025
Viewed by 678
Abstract
The conservation and restoration of water-gilded wooden cultural heritage, such as polychrome sculptures, frames, panels, altarpieces, etc., requires the use of fillers that guarantee structural stability, physicochemical and mechanical compatibility with the original support, and the ability to adapt to dimensional movements induced [...] Read more.
The conservation and restoration of water-gilded wooden cultural heritage, such as polychrome sculptures, frames, panels, altarpieces, etc., requires the use of fillers that guarantee structural stability, physicochemical and mechanical compatibility with the original support, and the ability to adapt to dimensional movements induced by thermo-hygrometric variations. This study, conducted as part of the DorART Project, analyzed the behavior of nine formulations, both commercial and non-commercial, selected through a review of the state-of-the-art specialized literature, along with the use of participatory science, which focused on the practices and materials most commonly used by professionals in the field. The experimental design was based on three types of specimens: two with wooden supports, selected for evaluating their interaction with the original material and with the traditional water gilding technique, and a third type for analyzing the individual behavior of the tested materials. Analyses of adhesion, tensile strength, Shore C hardness, gloss, abrasion test results, wettability, pH changes, and chemical composition were performed using ATR-FTIR spectroscopy. The results showed significant differences depending on the type of curing used and the composition and aging behavior of the specimen. Some of the fillers demonstrated improved compatibility with water-based gilding, facilitating workability and providing structural strength. M3 and M9 demonstrated an optimal balance of workability and aging stability. The results of this study can help restorers select materials based on their specific needs, considering the requirements of mechanical adaptation to the substrate, compatibility, and durability. Full article
Show Figures

Figure 1

27 pages, 36926 KiB  
Article
Comparison of Additive Manufacturing and Injection Molding of Biocomposites Reinforced with Alkali-Treated Wood Flour Derived from Recycled Wooden Pallets
by Mehmet Demir, Nilgül Çetin and Nasır Narlıoğlu
Polymers 2025, 17(15), 2004; https://doi.org/10.3390/polym17152004 - 22 Jul 2025
Viewed by 392
Abstract
Biodegradable polymer composites offer promising alternatives to petroleum-based plastics, supporting the principles of a zero waste and circular economy. This study investigates the reinforcing potential of alkali-treated wood flour derived from recycled pine (Pinus brutia Ten.) and poplar (Populus alba L.) [...] Read more.
Biodegradable polymer composites offer promising alternatives to petroleum-based plastics, supporting the principles of a zero waste and circular economy. This study investigates the reinforcing potential of alkali-treated wood flour derived from recycled pine (Pinus brutia Ten.) and poplar (Populus alba L.) waste wooden pallets in poly(lactic acid) (PLA) biocomposites. Wood flour was initially recovered through grinding and screening during recycling, followed by alkali treatment via a green chemistry approach to enhance interfacial bonding with the PLA matrix. The impact of alkali concentration and two fabrication methods—additive manufacturing (AM) and injection molding (IM)—on the properties of developed biocomposite materials was assessed through mechanical, physical, morphological, and thermal analyses. IM samples outperformed AM counterparts, with the IM PLA containing 30 wt% wood flour (alkali-treated with 10% solution) showing the highest mechanical gains: tensile (+71.35%), flexural (+64.74%), and hardness (+2.62%) compared to untreated samples. Moreover, the AM sample with 10 wt% wood flour and 10% alkali treatment showed a 49.37% decrease in water absorption compared to the untreated sample, indicating improved hydrophobicity. Scanning electron microscopy confirmed that alkali treatment reduced void content and enhanced morphological uniformity, while thermal properties remained consistent across fabrication methods. This work introduces a green composite using non-toxic materials and treatments, facilitating eco-friendly production aligned with zero waste and circular economy principles throughout the manufacturing lifecycle. Full article
(This article belongs to the Special Issue Polymer Composites: Structure, Properties and Processing, 2nd Edition)
Show Figures

Graphical abstract

18 pages, 4009 KiB  
Article
Impact of Thermo-Oxidative Aging on Flame Retardancy of Melamine Formaldehyde Particle Boards: Processes and Performance Degradation Analysis
by Shiyue Ling, Yanni Zhang, Dan Yang, Luoxin Huang and Yuchen Zhang
Fire 2025, 8(7), 274; https://doi.org/10.3390/fire8070274 - 11 Jul 2025
Viewed by 428
Abstract
Melamine formaldehyde particle boards (MFPBs), commonly utilized as a wooden decorative material in traditional architecture, demonstrate considerable performance deterioration with extended age, with reductions in essential flame retardancy and structural integrity presenting substantial risks to fire safety in structures. This research examines the [...] Read more.
Melamine formaldehyde particle boards (MFPBs), commonly utilized as a wooden decorative material in traditional architecture, demonstrate considerable performance deterioration with extended age, with reductions in essential flame retardancy and structural integrity presenting substantial risks to fire safety in structures. This research examines the impact of thermo-oxidative aging on the flame retardancy of MFPBs. The morphological evolution, surface composition, and flame-retardant characteristics of aged MFPBs were examined via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), limiting oxygen index (LOI), and cone calorimeter (CCT). The results indicate that thermo-oxidative aging (60 °C, 1440 h) markedly reduces the activation energy (E, by 17.05%), pre-exponential factor (A, by 68.52%), LOI value (by 4%, from 27.5 to 26.4), and time to ignition (TTI, by 17.1%, from 41 s to 34 s) while augmenting the peak mass loss rate (MHRR, by 4.7%) and peak heat release rate (pHRR, by 20.1%). Subsequent investigation indicates that aging impairs the char layer structure on MFPB surfaces, hastens the migration and degradation of melamine formaldehyde resin (MFR), and alters the dynamic equilibrium between “MFR surface enrichment” and “thermal decomposition”. The identified degradation thresholds and failure mechanisms provide essential parameters for developing aging-resistant fireproof composites, meeting the pressing demands of building safety requirements and sustainable material design. Full article
(This article belongs to the Special Issue Fire Prevention and Flame Retardant Materials)
Show Figures

Figure 1

25 pages, 4179 KiB  
Article
A Reflection on the Conservation of Waterlogged Wood: Do Original Artefacts Truly Belong in Public Museum Collections?
by Miran Erič, David Stopar, Enej Guček Puhar, Lidija Korat Bensa, Nuša Saje, Aleš Jaklič and Franc Solina
Heritage 2025, 8(7), 273; https://doi.org/10.3390/heritage8070273 - 9 Jul 2025
Viewed by 391
Abstract
The last decade has seen a transformative advancement in computational technologies, enabling the precise creation, evaluation, visualization, and reproduction of high-fidelity three-dimensional (3D) models of archaeological sites and artefacts. With the advent of 3D printing, both small- and large-scale objects can now be [...] Read more.
The last decade has seen a transformative advancement in computational technologies, enabling the precise creation, evaluation, visualization, and reproduction of high-fidelity three-dimensional (3D) models of archaeological sites and artefacts. With the advent of 3D printing, both small- and large-scale objects can now be reproduced with remarkable accuracy and at customizable scales. Artefacts composed of organic materials—such as wood—are inherently susceptible to biological degradation and thus require extensive, long-term conservation employing costly methodologies. These procedures often raise environmental concerns and lead to irreversible alterations in the wood’s chemical composition, dimensional properties, and the intangible essence of the original artefact. In the context of public education and the dissemination of knowledge about historical technologies and objects, 3D replicas can effectively fulfill the same purpose as original artefacts, without compromising interpretative value or cultural significance. Furthermore, the digital data embedded in 3D surface and object models provides a wealth of supplementary information that cannot be captured, preserved, or documented through conventional techniques. Waterlogged wooden objects can now be thoroughly documented in 3D, enabling ongoing, non-invasive scientific analysis. Given these capabilities, it is imperative to revisit the philosophical and ethical foundations of preserving waterlogged wood and to adopt innovative strategies for the conservation and presentation of wooden artefacts. These new paradigms can serve educational, research, and outreach purposes—core functions of contemporary museums. Full article
Show Figures

Figure 1

14 pages, 4406 KiB  
Article
Craftsmanship and Techniques of a Lacquered Ear Cup from the Ancient Nanyue Kingdom
by Lin Zheng, Xia Li, Zichen Zhao, Shuang’e Tian, Jianling Tang, Siming Li, Xiaocen Li, Na Wang and Tengfei Yu
Coatings 2025, 15(7), 752; https://doi.org/10.3390/coatings15070752 - 25 Jun 2025
Viewed by 408
Abstract
This study analyzes a lacquered ear cup excavated from the Luobowan tomb complex in Guigang, Guangxi, attributed to the Nanyue Kingdom of the early Han dynasty. A range of analytical techniques, including optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), [...] Read more.
This study analyzes a lacquered ear cup excavated from the Luobowan tomb complex in Guigang, Guangxi, attributed to the Nanyue Kingdom of the early Han dynasty. A range of analytical techniques, including optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD), were employed to investigate the structural layers, material composition, and preservation state of the artifact. The lacquerware consists of four traditional layers: a wooden core, fabric reinforcement, lacquer ground, and lacquer film, reflecting Central Plains lacquerware techniques. The wooden core was identified as Phoebe sp., and the fabric layer is likely hemp, though fiber degradation limited exact identification. The lacquer ground layer contains natural lacquer mixed with SiO2 from brick or tile powder. The lacquer film is a blend of Chinese and Vietnamese lacquer, with no synthetic additives or plant oils detected. The red lacquer layer contains cinnabar (HgS) as a pigment, while the black lacquer uses carbon black. Differences in moisture content between the red and black lacquer films are attributed to variations in surface porosity and pigment characteristics. This research provides valuable insights into Nanyue lacquer technology and preservation challenges. Full article
(This article belongs to the Special Issue Research and Conservation of Ancient Lacquer)
Show Figures

Figure 1

24 pages, 18896 KiB  
Article
Visual Discomfort in the Built Environment: Leveraging Generative AI and Computational Analysis to Evaluate Predicted Visual Stress in Architectural Façades
by Cleo Valentine, Arnold J. Wilkins, Heather Mitcheltree, Olivier Penacchio, Bruce Beckles and Ian Hosking
Buildings 2025, 15(13), 2208; https://doi.org/10.3390/buildings15132208 - 24 Jun 2025
Viewed by 1796
Abstract
The built environment is increasingly recognized as a critical determinant of human health, profoundly influencing neurophysiological and psychological well-being. Previous studies show that specific visual patterns can elicit cortical hyperexcitation and visual discomfort, particularly in individuals with a predisposition to cortical hyperexcitability. However, [...] Read more.
The built environment is increasingly recognized as a critical determinant of human health, profoundly influencing neurophysiological and psychological well-being. Previous studies show that specific visual patterns can elicit cortical hyperexcitation and visual discomfort, particularly in individuals with a predisposition to cortical hyperexcitability. However, traditional approaches to examining visual stress have yet to capture the complexity of ways in which the built environment may contribute to visual discomfort. This study presents a novel, integrated analytical methodology that merges generative artificial intelligence (using Midjourney v6.1) with advanced Fourier-based computational analysis to quantify the impact of architectural façades on visual stress. By systematically varying contrast ratios, pattern periodicity, spatial frequency distribution, stylistic elements, and geometric curvature across nine façade designs, the research generated a diverse array of stimuli that were then analyzed using the Visual Stress Analysis Tool (ViStA). This tool employs Fourier spatial frequency decomposition to extract key metrics that are proxy indicators of potential cortical stress responses. The results revealed that façades with regularly spaced elements at approximately three cycles per degree exhibited the highest stress metrics, particularly when combined with high contrast ratios and consistent repetition. Vertical wooden slats and vertical metal screening elements produced the most pronounced indicators of visual stress, while more varied geometric compositions demonstrated substantially lower stress metrics. This methodology offers a scalable, reproducible approach for the evaluation of visual stress. The framework lays the groundwork for developing a more robust evidence base to support architectural design decision-making that proactively addresses the health impacts of the built environment. Full article
(This article belongs to the Special Issue Urban Wellbeing: The Impact of Spatial Parameters—2nd Edition)
Show Figures

Figure 1

22 pages, 10281 KiB  
Article
From Flanders to Portugal: A Portuguese Painter in Pursuit of Prestigious Flemish Painting—Materials and Techniques Compared Through an Analytical Approach
by Vanessa Antunes, António Candeias, José Mirão, Sara Valadas, Ana Cardoso, Maria José Francisco, Alexandra Lauw, Marta Manso and Maria Luísa Carvalho
Heritage 2025, 8(6), 205; https://doi.org/10.3390/heritage8060205 - 3 Jun 2025
Viewed by 483
Abstract
This study offers fresh insights into the technical and stylistic exchanges between Flemish and Portuguese panel painting during the late 15th and early 16th centuries. By comparing two contemporaneous works, we trace Flemish influence in Portugal through a detailed materials and techniques analysis. [...] Read more.
This study offers fresh insights into the technical and stylistic exchanges between Flemish and Portuguese panel painting during the late 15th and early 16th centuries. By comparing two contemporaneous works, we trace Flemish influence in Portugal through a detailed materials and techniques analysis. Non-invasive, in situ methods—including energy dispersive X-ray fluorescence (XRF), macro-photography (MP), infrared reflectography (IRR), and dendrochronology—were used to examine each painting’s wooden support, ground layer, underdrawing, and pigment stratigraphy. Select micro-sampling analyses—micro-Fourier-transform infrared spectroscopy (μ-FTIR), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and micro-Raman spectroscopy (µ-Raman)—provided complementary data on binder and pigment composition. While both paintings share nearly identical pigments and layering sequences and employ comparable coating techniques, their ground compositions differ subtly. Notably, the Flemish work features extensive gold-leaf application, whereas underdrawing execution takes on principal importance in the Portuguese example. Together, these findings reveal that Jorge Afonso’s workshop developed a distinct Portuguese method—rooted in Flemish practices disseminated by Quentin Metsys—yet adapted to local materials and aesthetic priorities. Full article
Show Figures

Graphical abstract

17 pages, 1090 KiB  
Review
Overview and Evaluation of Chemicals and Methods for Flame Retardancy in Glued Laminated Wood Systems
by Ewelina Depczynska and Izabela Burawska
Polymers 2025, 17(11), 1459; https://doi.org/10.3390/polym17111459 - 24 May 2025
Viewed by 677
Abstract
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, [...] Read more.
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
Show Figures

Figure 1

34 pages, 22793 KiB  
Article
Spectral Raman Database of Modern Acrylic Paints at 532 nm and 633 nm Laser Excitation Wavelengths
by Irene Barba Castagnaro, Antonello Nucera, Marco Castriota, Riccardo Cristoforo Barberi, Jana Striova and Raffaella Fontana
Appl. Sci. 2025, 15(11), 5908; https://doi.org/10.3390/app15115908 - 23 May 2025
Viewed by 716
Abstract
Modern and contemporary artworks, due to technological developments in the synthesis of new pigments, are characterized by a pictorial palette composed of a wide variety of pigments. This diversity makes it increasingly important to carry out thorough characterization studies in order to gain [...] Read more.
Modern and contemporary artworks, due to technological developments in the synthesis of new pigments, are characterized by a pictorial palette composed of a wide variety of pigments. This diversity makes it increasingly important to carry out thorough characterization studies in order to gain a complete and comprehensive understanding of the properties of the numerous pigments in use today. In this work, 18 modern acrylic paints were characterized using micro-Raman spectroscopy with two laser excitation lines (532 nm and 633 nm). The analysed pigments can be classified as organic, inorganic, or mixtures, depending on their chemical composition. Specifically, the following pigments were investigated: Cobalt Blue, Permanent Blue Light, Ultramarine, Primary—Cyan Blue, Cerulean Blue, Cobalt Blue (Hue), Indanthrene Blue, Phthalo Blue, Van Dyke Brown, Permanent Green Light, Phthalo Green, Primary Red—Magenta, Cadmium Red Medium, Lemon Yellow, Cadmium Yellow Medium, Zinc White, Titanium White and Iridescent Silver. The pigments were applied to wooden and glass substrates to simulate the creative processes of actual modern and contemporary artworks. The aim was to define their composition, as this knowledge is essential for the protection, conservation and enhancement of cultural heritage. Full article
Show Figures

Figure 1

20 pages, 8603 KiB  
Article
First Identification of a Gypsum-Based Preparatory Layer on Polychrome Wooden Figurines from the Mawangdui Han Tomb No. 1 (2nd Century BCE), Changsha, China
by Ningning Xu, Tingyan Ren, Pan Xiao and Qi Liu
Coatings 2025, 15(4), 492; https://doi.org/10.3390/coatings15040492 - 21 Apr 2025
Viewed by 587
Abstract
This study presents the first scientific characterization of the white preparatory layer and polychrome pigments on painted wooden figurines excavated from the Mawangdui Tomb No. 1, dating to the Han dynasty. A combination of analytical techniques, including XRF mapping, SEM, ATR-FTIR, XRD, and [...] Read more.
This study presents the first scientific characterization of the white preparatory layer and polychrome pigments on painted wooden figurines excavated from the Mawangdui Tomb No. 1, dating to the Han dynasty. A combination of analytical techniques, including XRF mapping, SEM, ATR-FTIR, XRD, and Raman spectroscopy, was used to investigate the composition, structure, and potential additives in the white layer. The results reveal that the preparatory layer is primarily composed of gypsum (CaSO4·2H2O) and calcite (CaCO3), with minor phases such as anhydrite and larnite. SEM observations show a porous microstructure of needle-like crystals, while spectroscopic data suggest possible traces of organic binders. The preparatory layer was likely applied to smooth surface irregularities and support polychrome decoration, such as cinnabar and carbon-based pigments, and may have also functioned as a putty in localized areas. This represents the first confirmed use of gypsum-based plaster in ancient Chinese woodcarving, showing unexpected parallels with surface preparation techniques used in New Kingdom Egypt. However, the presence of organic additives and the internal structure of the figurines remain unresolved due to equipment limitations. These findings provide new insights into ancient material practices and highlight the importance of environmental control and material-specific conservation strategies for fragile gypsum-based heritage objects. Full article
Show Figures

Figure 1

14 pages, 5221 KiB  
Article
Recycling Bitumen for Composite Material Production: Potential Applications in the Construction Sector
by Ergo Rikmann, Uno Mäeorg, Neeme Vaino, Vello Pallav, Oliver Järvik and Jüri Liiv
Appl. Sci. 2025, 15(3), 1313; https://doi.org/10.3390/app15031313 - 27 Jan 2025
Viewed by 1280
Abstract
During roof renovations, large quantities of waste BBRM (bitumen-based roofing materials) are generated, and the possibilities for recycling these materials have so far been very limited. In general, they can be crushed and mixed with asphalt to pave roads or can be burned [...] Read more.
During roof renovations, large quantities of waste BBRM (bitumen-based roofing materials) are generated, and the possibilities for recycling these materials have so far been very limited. In general, they can be crushed and mixed with asphalt to pave roads or can be burned for energy. While waste plastic materials are often recycled, the remelting process significantly degrades their durability and mechanical properties. Unlike conventional methods, our recycling process results in a material with properties that are in many ways superior to the original materials. It is durable, weather resistant, and has exceptionally high mechanical strength. This material can be used to produce various construction components, including replacing quickly degradable wooden parts in structures. The composite material demonstrates increased flexibility, enhanced tensile strength, and improved resistance to ultraviolet (UV) radiation and environmental degradation compared to standard bitumen. The process is simple and can be carried out directly at the renovation site using a portable device. Full article
Show Figures

Figure 1

23 pages, 9139 KiB  
Article
Experimental and Numerical Simulation Study on the Mechanical Properties of Integrated Sleeve Mortise and Tenon Steel–Wood Composite Joints
by Zhanguang Wang, Weihan Yang, Zhenyu Gao, Jianhua Shao and Dongmei Li
Buildings 2025, 15(1), 137; https://doi.org/10.3390/buildings15010137 - 4 Jan 2025
Cited by 2 | Viewed by 1188
Abstract
In view of the application status and technical challenges of steel–wood composite joints in architecture, this paper proposes an innovative connection technology to solve issues such as susceptibility to pry-out at beam–column joints and low load-bearing capacity and to provide various reinforcement methods [...] Read more.
In view of the application status and technical challenges of steel–wood composite joints in architecture, this paper proposes an innovative connection technology to solve issues such as susceptibility to pry-out at beam–column joints and low load-bearing capacity and to provide various reinforcement methods in order to meet the different structural requirements and economic benefits. By designing and manufacturing four groups of beam–column joint specimens with different reinforcement methods, including no reinforcement, structural adhesive and angle steel reinforcement, 4 mm thick steel sleeve reinforcement, and 6 mm thick steel sleeve reinforcement, monotonic loading tests and finite element simulations were carried out, respectively. This research found that unreinforced specimens and structural adhesive angle steel-reinforced joints exhibited obvious mortise and tenon compression deformation and, moreover, tenon pulling phenomena at load values of approximately 2 kN and 2.6 kN, respectively. However, the joint reinforced by a steel sleeve showed a significant improvement in the tenon pulling phenomenon and demonstrated excellent initial stiffness characteristics. The failure mode of the steel sleeve-reinforced joints is primarily characterized by the propagation of cracks at the edges of the steel plate and the tearing of the wood, but the overall structure remains intact. The initial rotational stiffness of the joints reinforced with angle steel and self-tapping screws, the joints reinforced with 4 mm thick steel sleeves, and the joints reinforced with 6 mm thick steel sleeves are 3.96, 6.99, and 13.62 times that of the pure wooden joints, while the ultimate bending moments are 1.97, 7.11, and 7.39 times, respectively. Using finite element software to simulate four groups of joints to observe their stress changes, the areas with high stress in the joints without sleeve reinforcement are mainly located at the upper and lower ends of the tenon, where the compressive stress at the upper edge of the tenon and the tensile stress at the lower flange are both distributed along the grain direction of the beam. The stress on the column sleeve of the joints reinforced with steel sleeves and bolts is relatively low, while the areas with high strain in the beam sleeve are mainly concentrated on the side with the welded stiffeners and its surroundings; the strain around the bolt holes is also quite noticeable. Full article
(This article belongs to the Section Building Structures)
Show Figures

Figure 1

14 pages, 1797 KiB  
Article
Evaluation of Possible Contaminants from Sustainable Materials Intended for Food Contact
by Olimpia Pitirollo, Maria Grimaldi, Edmondo Messinese, Marco Fontanarosa, Monica Mattarozzi and Antonella Cavazza
Sustainability 2025, 17(1), 178; https://doi.org/10.3390/su17010178 - 29 Dec 2024
Viewed by 1694
Abstract
The ecological transition is leading industry towards the use of materials of natural origin, which are often proposed for food contact materials as a sustainable solution to reduce plastic use. They are perceived as safe by consumers; however, a strict control on potential [...] Read more.
The ecological transition is leading industry towards the use of materials of natural origin, which are often proposed for food contact materials as a sustainable solution to reduce plastic use. They are perceived as safe by consumers; however, a strict control on potential contaminants able to migrate to food and beverages is necessary to assess safety. Thus, the development of analytical methods for the detection and the identification of potentially occurring harmful substances is strongly encouraged, and the combination of different techniques can be a solution to obtain complementary information. In this work, GC-MS, HPLC-MS, ATR-IR and ESEM have been exploited with the aim of monitoring both volatile and non-volatile compounds, and to control surface composition and morphology. Extraction with solvent and migration experiments with simulants were performed on 11 commercial samples, including plates, caps, and wooden coffee stirrers. Global and specific migration studies were carried out, and possible differences before and after use were explored. Analysis after solvent extraction confirmed the presence of additives, and of Non-Intentionally-Added Substances (NIAS) that were also found in migration studies. Data on morphological characterisation were useful to control the item composition, and to check the stability of the materials after repeated use. Full article
(This article belongs to the Special Issue Sustainable Development in Food Quality and Safety)
Show Figures

Figure 1

18 pages, 5907 KiB  
Article
Improvement of Bending Stiffness of Timber Beams with Ultra-High-Modulus-Carbon-Fibre-Reinforced Polymer Sheets
by Michał Marcin Bakalarz and Paweł Grzegorz Kossakowski
Materials 2025, 18(1), 71; https://doi.org/10.3390/ma18010071 - 27 Dec 2024
Cited by 1 | Viewed by 793
Abstract
The bending stiffness of beams represents a pivotal parameter influencing both the dimensions of the elements during their design and their subsequent utilisation. It is evident that excessive deflections can cause discomfort to users and contribute to further structural degradation. The objective of [...] Read more.
The bending stiffness of beams represents a pivotal parameter influencing both the dimensions of the elements during their design and their subsequent utilisation. It is evident that excessive deflections can cause discomfort to users and contribute to further structural degradation. The objective of this study was to enhance the bending stiffness of timber beams by bonding a composite sheet to their external surfaces. A carbon sheet exhibiting an ultra-high modulus of elasticity and low elongation at rupture was employed. Two variables of analysis can be distinguished including whether the reinforcement was applied or not and the number of reinforcement layers. The beams, with nominal dimensions of 80 × 80 × 1600 mm, were subjected to a four-point bending test in order to ascertain their mechanical properties. In total, 15 beams were tested (5 unreinforced and 10 reinforced). The reinforcement had no appreciable impact on the increase in flexural load capacity, with the maximum average increase recorded at 9%. Nevertheless, an increase in stiffness of 34% was observed. Additionally, significant increases were observed in ductility up to 248%. However, the ductile behaviour of the beam occurred after the rupture of the reinforcement. In all instances, the failure was attributed to the fracturing of the wooden components or the UHM CFRP (ultra-high-modulus-carbon-fibre-reinforced polymer) sheet. The numerical analysis proved to be a valuable tool for predicting the stiffness of the wood–composite system, with a relatively low error margin of a few percentage points. The modified approach, based on the equivalent cross-section method, permits the determination of a bilinear load deflection relationship for reinforced beams. The aforementioned curve is indicative of the actual behaviour. Given the propensity for the sudden rupture of reinforcement, the described method of reinforcement is recommended for beams subjected to lower levels of stress. Full article
Show Figures

Figure 1

Back to TopTop