1. Thermal energy storage and leakage prevention of phase change materials via one-step impregnation and in-situ polymerization process in hardwoodJakub Grzybek, Gabriel Zsembinszki, Emiliano Borri, Alina Meindl, Zuzana Paschová, Alexander Petutschnigg, Luisa F. Cabeza, Thomas Schnabel, 2026, original scientific article Abstract: Wood is a versatile material widely used in building construction, but its low thermal mass limits its ability to regulate indoor temperatures and mitigate thermal load peaks. Phase change materials are effective at storing thermal energy, but when impregnated into wood, they leak out, compromising performance and restricting their use in buildings. This study introduces a novel one-step impregnation process combined with in-situ polymerization using furfuryl alcohol and a capric-stearic acid phase change material mixture to create a sustainable material for thermal energy storage. Various formulations were tested on European beech (Fagus sylvatica L.) to evaluate effectiveness of the approach. The results confirm that this method successfully prevents phase change material leakage. Moreover, differential scanning calorimetry and nuclear magnetic resonance verified that phase change materials retain their thermal energy storage functionality, with no chemical cross-linking between the phase change materials and furfuryl alcohol. The treated wood showed up to 185 % higher thermal energy storage capacity, enhanced dimensional stability (anti-swelling efficiency up to 87 %), and 28 % higher compressive strength than untreated wood. It is a step towards sustainable, multifunctional, leakage-free, enhanced mechanical properties, improved dimensional stability wood for thermal energy storage for building applications, with potential for further optimisation and characterisation. Keywords: bio-based materials, fatty acid, furfuryl alcohol, sustainable building materials, wood modification, phase change materials Published in RUP: 09.01.2026; Views: 105; Downloads: 3
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2. Consumer perceptions of wood as a material for sustainable building construction in SloveniaAna Slavec, Lea Primožič, Nežka Sajinčič, 2025, published scientific conference contribution Abstract: In the context of climate change, aligning residential building practices with environmental priorities is increasingly important. Wood products, with their lower carbon footprint compared to most alternatives, present a viable solution for more sustainable construction. However, consumer awareness of these benefits remains limited. While interest in sustainability is rising, many consumers still perceive wooden structures as less durable, more vulnerable to fire and earthquakes, harder to insulate, and more expensive to maintain. Additionally, environmental considerations often rank below cost, design, and durability when selecting materials for construction, furnishing, and renovations. To explore these perceptions, we conducted a quantitative survey in 2023 involving 1,009 participants from a representative marketing panel in Slovenia. The study assesses Slovenian consumers’ environmental identity, climate concerns, and the frequency of eco-friendly choices, while examining the importance of sustainability relative to other factors in home design decisions. We further analyse the prevalence of wood-based materials in Slovenian households and gather insights on attitudes toward wood in construction. Our findings highlight the need for targeted communication campaigns to address consumer misperceptions about wood’s durability and environmental benefits, drawing comparisons with past studies from other countries. This research provides actionable recommendations for policymakers and industry stakeholders to enhance consumer engagement and support the adoption of wood as a sustainable building material. Keywords: survey research, wood, sustainable construction Published in RUP: 23.12.2025; Views: 129; Downloads: 2
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3. Review on the structure-property relationship of lignocellulosic materials measured by atomic force microscopyJuan Li, Bohumil Kasal, 2025, review article Abstract: In this review, we provide an overview of how atomic force microscopy (AFM) measurements on wood or other plant fibers help us understand the structure–property relationship in growing plants, matured wood material, and wood modifications and aging. We selected wood as a model material that can represent a number of lignocellulosic systems and attempted to address the structure–property relationship, as studied in situ. We selected AFM because it allows scientists to study materials in an unaltered, in situ form and relate chemical composition to material properties at a nanoscale level. We summarized the high-resolution measurements of wood cell walls such as topography, adhesion force, modulus, and chemical functional groups using AFM. Our three focus areas were: (1) how the cell wall develops its structure and property in living trees; (2) how the ultrastructure determines cell wall property; and (3) how the modification/aging of the cell wall changes its property in application scenarios. Keywords: wood, fibres, structure Published in RUP: 23.12.2025; Views: 142; Downloads: 2
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4. Experimental and analytical evaluation of shear capacity of reclaimed timber connections with thermo-mechanically densified wooden dowelsMohammad Derikvand, Donya Bazyar Khoshroodi, 2025, original scientific article Abstract: The reuse of reclaimed timber in structural applications is increasingly recognized as a strategy to extend ma- terial life cycles and reduce waste. Particular attention has recently turned to reusing reclaimed timber in adhesive-free laminated products with wooden dowels, where connection performance is critical. The aim of this study was to investigate the mechanical performance of double-shear connections assembled from reclaimed spruce timber using thermo-mechanically densified wooden dowels. The dowels were first evaluated in bending and embedment tests on lamellae made from both reclaimed and virgin spruce timber. The shear capacity of the connections was then evaluated in three layups: two homogeneous (all-reclaimed lamellae and all-virgin spruce lamellae) and one hybrid (reclaimed side lamellae with a central virgin spruce lamella). Analytical predictions were performed based on the draft of the new Eurocode 5, however, with two alternative definitions of dowel bending resistance (ultimate moment Mu and yield moment My), and three alternative definitions of embedment strength (f 0.05d h calculated using the 0.05 d offset method, f Fmax h calculated from Fmax, and f 0.8Fmax h calculated from 0.8 Fmax). The three lamellae layups exhibited relatively similar mean capacities (7.3–8.3 kN). The all-reclaimed connections were on average 13 % stronger than the other assemblies, but this was not statistically significant. Among the model input variants, Mu with f 0.05d h showed the closest agreement with the experimental mean values, while My with f 0.05d h led to more conservative predictions preferable for design. In both cases, excluding outliers from the embedment test results reduced overestimation in the predictions. All other input variants overestimated the shear capacity. Overall, both homogeneous and hybrid connections with reclaimed timber lamellae performed comparably to virgin timber connections and exhibited predictable mechanical behavior. Keywords: reclaimed timber, wood densification, structural reuse, embedment strength, dowel connections, European yield model, Eurocode 5 Published in RUP: 17.12.2025; Views: 157; Downloads: 2
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5. BIM-based framework for estimating service life duration of wood construction elements under environmental exposureRichard Acquah, Jonas Niklewski, Anna Malgorzata Sandak, Jakub Michal Sandak, 2026, original scientific article Abstract: As the construction industry adopts more data-driven and sustainable practices, Building Information Modelling (BIM) is increasingly used for energy analysis, lifecycle management, and maintenance planning. However, its integration with service life performance analysis especially for wood, a material susceptible to environmental degradation remains limited. This study presents a BIM-based framework that incorporates wood-specific parameters such as environmental exposure, material properties, and design detailing to estimate the service life of wood construction elements. The framework is structured using ISO 15,686–4 principles and implemented through custom Industry Foundation Classes (IFC) property sets. A Revit plugin developed in C# integrates the model into the BIM environment. A case study of a wooden playhouse is used as a proof-of-concept to demonstrates the framework’s ability to evaluate the impact of design, material, and environmental factors on service life. The results confirm that the framework supports service life prediction and enhances decision-making for wood-based construction. Twenty-one-month observations align with predicted results. However, long-term (2–9 year) predictions remain unvalidated, requiring extended monitoring. By integration of the service life prediction for fungal decay into BIM it offers a practical and scalable tool to support service life–informed design and planning for wood structures. Keywords: service life prediction, wood material durability, environmental exposure, wood 28 construction, sustainable construction, building information modelling (BIM) Published in RUP: 24.11.2025; Views: 307; Downloads: 9
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6. Size effect on bending strength and failure modes of finger-jointed timberMohammad Derikvand, Michael David Burnard, Donya Bazyar Khoshroodi, Rok Barbič, Marko Vouk, Andreja Kutnar, 2025, original scientific article Abstract: Finger-jointed timber boards for cross-laminated timber production are typically assigned the same characteristic bending strength (fm,j,k) if produced from the same strength class, regardless of differences in their cross-sectional dimensions. To validate the relevance of this approach, this study investigated the effects of cross-sectional dimensions on the bending performance of finger-jointed timber produced from spruce (strength class: C24). A large industrial dataset of 1100 specimens, with seven thicknesses (ranging 20 to 40 mm) and variable widths, were statistically analyzed. The bending tests were performed with a constant span-to-depth ratio (l/h = 18), meaning thinner specimens had a shorter test span. Bending strength was modeled with Bayesian multilevel linear model, and the proportions of three quality-control failure modes (joint interface failure, joint base failure, and outside-joint failure) were analyzed with a zero-one-inflated Dirichlet regression. Based on the results, all groups with n ≥ 100 exceeded the declared fm,j,k of 27.6 MPa, with characteristic strengths of 43.7 MPa (+58.3 %), 40.0 MPa (+45.0 %), and 38.3 MPa (+38.8 %) for the 20-, 30-, and 40-mm thickness groups, respectively. Thinner specimens demonstrated higher bending strength with convincing evidence (pairwise contrasts PD = 100 % with 95 % HDPIs entirely below zero), while width had no credible effect (PD < 95 %). Dirichlet regression revealed shifts in failure mode proportions with varying strength. Higher bending strengths were associated with a higher proportion of joint interface failure. Outside‑joint failure was observed with a higher proportion in lower-strength and thicker specimens. Overall, assigning uniform fm,j,k to various cross-sectional dimensions proved to give adequate safety margins. Beyond the uniform fm,j,k, however, statistical evidence of a size effect on both bending strength and failure modes was observed. The magnitude of the observed size effect reflects the combined influence of increasing thickness and test span under the current quality control bending test regime, which means a coupled change in stressed volume and geometry rather than a pure cross-section scaling effect. These findings are relevant to flatwise four-point bending tests on finger-jointed boards from industrial production made with visually graded C24 spruce with thickness ranging 20 to 40 mm. Keywords: wood, finger joint, strength Published in RUP: 18.11.2025; Views: 308; Downloads: 5
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8. Combining thermo-hydro- mechanical and phenol-resin impregnation treatments : potential for high-density poplar flooringMatthew Schwarzkopf, 2020, other scientific articles Abstract: Thermo-hydro-mechanical (THM) treatments can be used to improve certain properties of underutilized wood species, especially those with low densities. These treatments densify the wood by softening the cell walls using heat, pressure, and moisture but are subject to set-recovery (recovery of compressive deformation) when exposed to humidity. Phenol-based resins have been successful in mitigating this issue when impregnated into the wood. This work explores the use of a new phenol-based resin combined with a THM treatment to limit set-recovery and produce products with the potential for flooring applications. Scratch resistance, hardness, and glue-line shear strength were used to assess the performance. The THM treatment and impregnated phenol resin used in this study increased the scratch resistance, density, and hardness of natural poplar wood and created satisfactory bonding conditions for flooring purposes. With optimization of THM parameters and resin solids content, the resulting product could provide a high-quality flooring material used alone or as a thin laminate from a low-density species like poplar Keywords: densified wood, impregnation, phenol resin Published in RUP: 25.07.2025; Views: 654; Downloads: 5
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9. Auditory emotional design in multimedia learning : educational videos on wood as a building materialNežka Sajinčič, 2024, doctoral dissertation Keywords: multimedia learning, auditory emotional design, instructor’s voice, emotional tone, background music, same-language subtitles, learning in a foreign language, wood as a building material Published in RUP: 14.10.2024; Views: 1431; Downloads: 51
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