Search Results (281)

The main aim of this work is to compare double- or single-designed connections with wooden members and internal steel fasteners under fire conditions. Theoretical methods following Eurocodes will be used to assess the load-bearing capacity of the connections and to compare the effects of double and single shear. Several parameters will be examined to determine the load capacity. Furthermore, a numerical thermal analysis using finite element methods will be performed to estimate the temperatures inside the connections and compare them. The results show that the double shear connection in steel-to-timber, with a steel plate of any thickness as the central element and with a higher density of wood material, has better mechanical and fire resistance. Lower temperatures were also observed in this connection type in the wood material and along the length of the dowel. Full article

Offsite construction (OSC) offers a promising alternative for accelerating refurbishment projects across Italy and Europe. However, its adoption remains limited due to technical, regulatory, and cultural barriers. This study, conducted as part of the OFFICIO project, maps the current European OSC landscape, with a focus on wood and light-steel technologies for sustainable building refurbishment. Combining a literature review, analysis of funded projects, and market data for 541 OSC products, the study develops tailored KPIs to assess these products’ technical maturity, prefabrication level, and environmental integration. The results reveal that wood-based OSC, although less widespread, is more mature and centered on the use of multi-layer panels, while steel-based systems, though more prevalent, remain largely tied to semi-offsite construction, indicating untapped development potential. Research efforts, especially concentrated in Mediterranean regions, focus on technological integration of renewable energy systems. A significant literature gap was identified in information concerning panel-to-wall connection, critical for renovation, limiting OSC’s adaptability to regeneration of existing buildings. The findings highlight the need for cross-sector collaboration, legislative clarity, and better alignment of public procurement standards with OSC characteristics. Addressing these issues is essential to bridge the gap between research prototypes and industrial adoption and accelerate the sustainable transformation of Europe’s construction sector to help meet climate neutrality targets. Full article

Rural areas around the world are increasingly dealing with energy and environmental challenges. These challenges are particularly acute in developing countries, where persistent reliance on traditional energy sources—such as wood fuel—intersects with concerns about forest conservation and energy sustainability. While wood fuel use is often portrayed as unsustainable, it is important to acknowledge that much of it remains ecologically viable and socially embedded. This study explores the role of rural entrepreneurs in shaping low-carbon transitions at the intersection of household energy practices and environmental stewardship. Fieldwork was carried out in four rural Zambian communities in 2016 and complemented by 2024 follow-up reports. It examines the connections between household energy choices, greenhouse gas emissions, and forest resource dynamics. Findings reveal that over 60% of rural households rely on charcoal for cooking, with associated emissions estimated between 80 and 150 kg CO₂ per household per month. Although this is significantly lower than the average per capita carbon footprint in industrialized countries, such emissions are primarily biogenic in nature. While rural communities contribute minimally to global climate change, their practices have significant local environmental consequences. This study draws attention to the structural constraints as well as emerging opportunities within Zambia’s rural energy economy. It positions rural entrepreneurs not merely as policy recipients but as active agents of innovation, environmental monitoring, and participatory resource governance. A model is proposed to support sustainable rural energy transitions by aligning forest management with context-sensitive emissions strategies. Full article

This paper presents an integrated computational framework for predicting temperature fields in glulam beam–column connections under fire conditions, combining finite element modeling, automated parametric analysis, and deep learning techniques. A high-fidelity heat transfer finite element model was developed, incorporating the anisotropic thermal properties of wood and temperature-dependent material behavior, validated against experimental data with strong agreement. To enable large-scale parametric studies, an automated Abaqus model modification and data processing system was implemented, improving computational efficiency through the batch processing of geometric and material parameters. The extracted temperature field data was used to train a DeepONet neural network, which achieved accurate temperature predictions (with a L2 relative error of 1.5689% and an R² score of 0.9991) while operating faster than conventional finite element analysis. This research establishes a complete workflow from fundamental heat transfer analysis to efficient data generation and machine learning prediction, providing structural engineers with practical tools for the performance-based fire safety design of timber connections. The framework’s computational efficiency enables comprehensive parametric studies and design optimizations that were previously impractical, offering significant advancements for structural fire engineering applications. Full article

Fast-growing hardwoods like poplar often lack natural durability in outdoor use and require homogeneous impregnation with protective agents, though achieving homogeneity remains a known challenge. Various anatomical structures influence fluid transport in wood. This study compares characteristics of pits in libriform fibres, between ray–vessel interfaces, and between vessel-to-vessel connections in normal wood and tension wood of a hybrid poplar genotype (Populus × canadensis, ‘Gelrica’), including both impregnated (with an aqueous, dye-containing solution) and non-impregnated regions, to identify anatomical barriers to impregnation. Light and scanning electron microscopy revealed significant differences in pit morphology and frequency in libriform fibres between normal wood and tension wood. In non-impregnated regions, pits were often encrusted. Vessel–ray pits did not differ between normal wood and tension wood but showed distinct differences between impregnated and non-impregnated regions: in the latter, pits were occluded by tylose-forming layers. Intervessel pits differed in border and aperture size between earlywood and latewood in both normal wood and tension wood. Hence, fluid transport is strongly impeded by occluded vessel–ray pits and, to a lesser extent, by encrusted fibre pits. Full article

Archeological structures connected with iron metallurgy were identified in the outskirts of the town Lučenec, Slovakia. Based on the shapes and decoration of the ceramic fragments, it was possible to date them to the 9th or 10th century. The first group of discovered metallurgical materials included slags with low wüstite content, which looks like slag from younger higher-shaft furnaces. The second group included slags which could be attributed to the technology common at the time of the site’s existence: iron smelting in lower free-standing shaft furnaces with average efficiency. The third group were slags from the forging of iron blooms to remove pores and slag particles. The fourth group consisted of ceramics fragments (tuyeres and refractory material). Bog ore was probably smelted using principally oak wood charcoal. Full article

This paper presents LokAlp, a modular timber construction system invented and developed by the authors, inspired by the traditional Blockbau technique, and designed for circularity and self-construction. LokAlp utilizes standardized interlocking blocks fabricated from CLT and GLT off-cuts to optimize material reuse and minimize waste. The study explores the application of massive timber digital materials within an open modular system framework, offering an alternative to the prevailing focus on lightweight structural systems, which predominantly rely on primary engineered wood materials rather than reclaimed by-products. The research evaluates geometric adaptability, production feasibility, and on-site assembly efficiency within a computational design and digital fabrication workflow. The definition of the LokAlp system has gone through several iterations. A full-scale demonstrator constructed using the LokAlp final iteration (Mk. XII) incorporated topological enhancements, increasing connection variety and modular coherence. Comparative analyses of subtractive manufacturing via 6-axis robotic milling versus traditional CNC machining revealed a >45% reduction in cycle times with robotic methods, indicating significant potential for sustainable industrial fabrication; however, validation under operational conditions is still required. Augmented reality-assisted assembly improved accuracy and reduced cognitive load compared to traditional 2D documentation, enhancing construction speed. Overall, LokAlp demonstrates a viable circular and sustainable construction approach combining digital fabrication and modular design, warranting further research to integrate robotic workflows and structural optimization. Full article

The study of cultural landscapes has a tradition stretching back several decades. During this time, methods have been developed based on the geographical data and technological capabilities available. However, with new data becoming available, new methodological and conceptual challenges arise in linking different types of landscape data. In our article, we attempt to address these challenges. These include historical maps and remote sensing data, such as aerial and satellite images and LiDAR data. We illustrate these using examples of traditional heritage landscapes in Slovakia. We critically evaluated the informational value of historical maps and their connection with remote sensing data. Our case studies focused on using LiDAR data to identify overgrowing processes, historical trackways, agricultural terraces, catchworks and tree vegetation in wood pastures. Digital technology provides new and more accurate data, as well as new ways of evaluating it, thereby enriching existing landscape ecological methods of cultural landscape research. Full article

We designed detachable steel sleeves to reinforce wooden joints and improve their integrity under earthquake action and investigated their mechanical properties. Monotonic bending tests were performed on a half-tenon pure wooden joint and a joint strengthened by a detachable steel sleeve. More obvious tenon pulling-out failure was observed in the pure wood joint; in comparison, only slight extrusion fracture of wooden beams and extrusion deformation of steel sleeves occurred in the wood joint reinforced by a detachable steel sleeve. Our test results showed that the initial rotational stiffness of the strengthened joint, JG1, was increased by 495.4% compared with that of the unstrengthened joint, JG0. The yield bending moment increased by 425.9%, and the ultimate bending moment increased by 627.5%, which indicated that the mechanical performance was significantly improved when the joint was reinforced by a detachable steel sleeve. Numerical simulations of different components were performed with finite element analysis software to analyze the mechanical performance of the reinforced joint. It was found that the stiffness and ultimate flexural performance of the joint could be increased by setting stiffeners on the steel sleeve and connecting the wooden column with self-tapping screws. The results of the tests were compared with those obtained through finite element analysis, and a high degree of accuracy was achieved, which could provide a theoretical basis for the reinforcement of timber structural buildings. Full article

The corrosion-induced strength degradation of steel nails poses a critical challenge to the structural integrity of timber connection joints, particularly in hygrothermal environments. Compressed wood nails exhibit hygroscopic expansion characteristics, demonstrating their potential as a sustainable alternative to steel nails in structural connections. However, systematic investigations on their shear performance under cyclic hygrothermal conditions remain limited. This study comparatively analyzed the shear behavior evolution of compressed wood nail and galvanized steel nail connections under wet-dry cycles. Distinct failure mechanisms were observed: wood nail connections exhibited characteristic brittle fracture patterns, whereas steel nail connections demonstrated ductile failure through pull-out deformation with nail bending. Notably, compressed wood nails displayed superior environmental stability, with significantly lower degradation rates in terms of load-bearing capacity (2.8% vs. 22.3%) and stiffness (16.3% vs. 38.0%) than their steel counterparts under identical hygrothermal exposure. These findings provide critical design references and data support for implementing wood-based fasteners in moisture-prone engineering applications. Full article

Red wood ants (RWA), belonging to the Formica rufa species group, play a crucial and fascinating role in Central Europe’s forest ecosystems. They have a high variety of effects, which they exert around their nests. Their generalist feeding on prey in the canopies of trees lowers the frequency of defoliator outbreaks, as well as increases local biodiversity. Nearly half of their diverse diet is insects, including species considered harmful by foresters. They also have a mutualistic relation with honeydew-producing aphids and planthoppers, which connection has unclear effects on the forests. The habit of RWAs building nests could also positively influence soil composition, due to its structure and high amount of organic matter, which could potentially benefit tree growth. RWAs are also known to enhance the species richness of forests by supporting various myrmecophilous species associated with them. In this study, we review the role of RWAs in forest protection, drawing on the literature focusing on Hungary and Central Europe. Full article

Costa Rica is located along the narrow isthmus that connected South America to North America beginning in the mid-Cenozoic. The exchange of vertebrates between the two continents has received considerable study, but paleobotanical aspects are less known. The Pacific coast “ring of fire” volcanoes produced abundant hyaloclastic material that provided a source of silica for wood petrifaction, and the tropical forests contained diverse taxa. This combination resulted in the preservation of petrified wood at many sites in Costa Rica. Fossil wood ranges in age from Lower Miocene to Middle Pleistocene, but Miocene specimens are the most common. Our research involved the study of 54 specimens, with the goal of determining their mineral compositions and interpreting the fossilization processes. Data came from thin-section optical microscopy, SEM images, and X-ray diffraction. Two specimens were found to be mineralized with calcite, but most of the woods contained crystalline quartz and/or opal-CT. The preservation of anatomical detail is highly variable. Some specimens show evidence of decay or structural deformation that preceded mineralization, but other woods have well-preserved cell structures. This preliminary study demonstrates the abundance and botanical diversity of fossil wood in Costa Rica, hopefully opening a door into future studies that will consider the taxonomy and evolutionary aspects of the country’s fossil forests. Full article

Mining significantly impacts terrestrial ecosystems despite its importance to the global economy. As part of soil ecosystems, fungi are highly responsive to environmental and human-induced drivers, shifting community composition and structure. Indeed, fungi play a key role in maintaining ecosystem resilience. Thus, we aim to address the question of whether soil fungal communities maintain similar ecological functions despite changes in community composition due to the impact of mining across ecosystems. To evaluate the ecological role of fungi across four ecosystems with varying iron mining impact levels, we used the FUNGuild database to assign functional guilds at the genus level. Co-occurrence network and ordination analyses were used to infer ecological relationships among fungal taxa and visualize the correlation between edaphic properties and fungal communities. A total of 22 functional guilds were identified, with dung saprotrophs, wood saprotrophs, fungal parasites, plant pathogens, ectomycorrhizal fungi, animal pathogens, and endophytes being the most abundant. Soil properties such as pH, organic matter, texture, and nutrients drive taxonomic and functional shifts. Our findings indicate that while mining activities shift fungal community compositions across ecosystems, the profiles of functional guilds show overlap between highly, moderately, and lowly impacted ecosystems, indicating functional redundancy. Network analysis reveals that highly connected hub taxa contribute to ecological redundancy across ecosystems and might act as a buffer against environmental disturbances. Our findings emphasize the important ecological role of soil fungi and indicate a potential for using fungal communities as bioindicators of ecological recovery in post-mining landscapes. From a mining and restoration perspective, this offers a low-cost, ecologically meaningful tool for monitoring soil recovery and guiding reclamation efforts. Full article

Wood displays three-dimensional characteristics at both macroscopic and microscopic scales. Accurately reconstructing its 3D structure is vital for a deeper understanding of the relationship between its anatomical characteristics and its physical and mechanical properties. This study aims to apply X-ray micro-computed tomography (XμCT) for the high-resolution, non-destructive visualization and quantification of softwood anatomical features. Six typical softwood species—Picea asperata, Cupressus funebris, Pinus koraiensis, Pinus massoniana, Cedrus deodara, and Pseudotsuga menziesii—were selected to represent a range of structural characteristics. The results show that a scanning resolution of 1–2 μm is suitable for investigating the transition from earlywood to latewood and resin canals, while a resolution of 0.5 μm is required for finer structures such as bordered pits, ray tracheids, and cross-field pits. In Pinus koraiensis, a direct 3D connection between radial and axial resin canals was observed, forming an interconnected resin network. In contrast, wood rays were found to be distributed near the surface of axial resin canals but without forming interconnected structures. The three-dimensional reconstruction of bordered pit pairs in Pinus massoniana and Picea asperata clearly revealed interspecific differences in pit morphology, distribution, and volume. The average surface area and volume of bordered pit pairs in Pinus massoniana were 1151.60 μm² and 1715.35 μm³, respectively, compared to 290.43 μm² and 311.87 μm³ in Picea asperata. Furthermore, XμCT imaging effectively captured the morphology and spatial distribution of cross-field pits across species, demonstrating its advantage in comprehensive anatomical deconstruction. These findings highlight the potential of XμCT as a powerful tool for 3D analysis of wood anatomy, providing deeper insight into the structural complexity and interconnectivity of wood. Full article

Cellulose, a widely abundant natural polymer, is well recognized for its remarkable properties, such as biocompatibility, degradability, and mechanical strength. Conductive hydrogels, with their unique ability to conduct electricity, have attracted significant attention in various fields. The combination of cellulose and conductive hydrogels has led to the emergence of cellulose-based conductive hydrogels, which show great potential in flexible electronics, biomedicine, and energy storage. This review article comprehensively presents the latest progress in cellulose-based conductive hydrogels. Firstly, it provides an in-depth overview of cellulose, covering aspects like its structure, diverse sources, and classification. This emphasizes cellulose’s role as a renewable and versatile material. The development and applications of different forms of cellulose, including delignified wood, bacterial cellulose, nanocellulose, and modified cellulose, are elaborated. Subsequently, cellulose-based hydrogels are introduced, with a focus on their network structures, such as single-network, interpenetrating network, and semi-interpenetrating network. The construction of cellulose-based conductive hydrogels is then discussed in detail. This includes their conductive forms, which are classified into electronic and ionic conductive hydrogels, and key performance requirements, such as cost-effectiveness, mechanical property regulation, sensitive response to environmental stimuli, self-healing ability, stable conductivity, and multifunctionality. The applications of cellulose-based conductive hydrogels in multiple areas are also presented. In wearable sensors, they can effectively monitor human physiological signals in real time. In intelligent biomedicine, they contribute to wound healing, tissue engineering, and nerve regeneration. In flexible supercapacitors, they offer potential for green and sustainable energy storage. In gel electrolytes for conventional batteries, they help address critical issues like lithium dendrite growth. Despite the significant progress, there are still challenges to overcome. These include enhancing the multifunctionality and intelligence of cellulose-based conductive hydrogels, strengthening their connection with artificial intelligence, and achieving simple, green, and intelligent large-scale industrial production. Future research directions should center around exploring new synthesis methods, optimizing material properties, and expanding applications in emerging fields, aiming to promote the widespread commercialization of these materials. Full article