1. Wood modification using Fast Pyrolysis Bio-Oil (FPBO) : formulation development, characterization, and evaluation of wood performanceAnna Malgorzata Sandak, Faksawat Poohphajai, Amina Selmanović, Rene Alexander Herrera Diaz, Jakub Grzybek, Kelly Peeters, Sasikala Perumal, Edit Földvári-Nagy, Lei Han, Richard Acquah, Jakub Michal Sandak, 2026, izvirni znanstveni članek Opis: This study presents a wood modification process using Fast Pyrolysis Bio-Oil (FPBO) as a fully biobased alternative to conventional, fossil-based and potentially toxic preservatives such as copper salts, organic biocides, and creosote. Standard FPBO was used in the devel- opment of 10 formulations, which were systematically characterized in terms of pot life, viscosity evolution, density, and pH. Radiata pine samples were subsequently impregnated using a bench-scale reactor, with specimens prepared in multiple geometries to assess treat- ment performance across different dimensions. The modified wood was comprehensively characterized with respect to moisture uptake, dimensional stability, density, mechanical strength, fixation efficiency, biological durability, and VOC emissions. Additional screening focused on properties relevant to outdoor applications, including aesthetic appearance and colour uniformity after UV exposure. The results enabled the identification of three top-performing formulations, treatments H, A, and E, which exhibited the most favourable balance between durability, environmental performance, and structural integrity. Overall, the findings demonstrate the strong potential of FPBO-based impregnation as a sustainable, multifunctional, and high-performance alternative for advanced wood protection systems.
Ključne besede: wood modification, fast pyrolysis bio-oil (FPBO), durability, bio-based impregnation treatment
Objavljeno v RUP: 29.06.2026; Ogledov: 197; Prenosov: 4
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2. Long-term durability of flax-glass hybrid FRP-timber composite structures subjected to hygrothermal environment : experimental and simulationSilu Huang, Libo Yan, Bohumil Kasal, Wei Yang, 2025, izvirni znanstveni članek Opis: This paper focuses on the experimental and numerical analysis of long-term performance of flax-glass hybrid FRP (HFRP)-laminated veneer lumber (LVL) joints and beams subjected to hygrothermal environment (50℃ and 95 %RH) for six months. The joints and beams with different fibre fabric stacking sequences of HFRP exposed at different exposure intervals (0, 1, 2, 3 and 6 months) were tested under block shear and four-point bending, respectively. The tensile properties of epoxy and HFRP composites under those exposure intervals were also examined to explore degradation mechanisms of HFRP in LVL-HFRP beams. Tensile strength and strain of HFRP showed a major reduction (26.7 – 32.1 %) in the first month of exposure. Hydrolysis and oxidation of epoxy were found to have insignificant effects on HFRP tensile properties, based on Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) results. A significant decrease (34.7 – 35.7 %) of LVL-HFRP joints in their shear strength was attributed to weakened hydrogen bonds between cellulose and lignin-hemicellulose matrix, along with the degradation and softening of hemicellulose. LVL-GF beams in which the glass fibre layer of HFRP was adhered to LVL exhibited a major reduction in bending strength (23.4 %) after the first month of exposure. In LVL-FG beams where the flax fibre layer was adhered to LVL, a major decrease in bending strength (25.8 %) was observed after two-month exposure. The postponed reduction in LVL-FG beams compared with LVL-GF beams was caused by the slower moisture diffusion in HFRP of LVL-FG beams than that in LVL-GF beams. A diffusion–stress coupled finite element (FE) model was developed, incorporating moisture diffusion and moisture-dependent mechanical properties for both the timber and HFRP components. Based on this model, the flexural response of LVL–HFRP beams after hygrothermal exposure was simulated, showing satisfactory agreement with experimental results. This research developed a step towards the long-term performance evaluation of HFRP-timber composite structures with different fabric stacking sequences of HFRP.
Ključne besede: long-term durability, hybrid FRP, timber-hybrid FRP composite structure
Objavljeno v RUP: 23.12.2025; Ogledov: 708; Prenosov: 3
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3. 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, izvirni znanstveni članek Opis: 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.
Ključne besede: service life prediction, wood material durability, environmental exposure, wood 28 construction, sustainable construction, building information modelling (BIM)
Objavljeno v RUP: 24.11.2025; Ogledov: 804; Prenosov: 18
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