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Arctic driftwood can be used as an alternative source of wood as construction timber and furniture material, especially in Iceland and Greenland. The use of Arctic driftwood can help in the fight against climate change, by developing land reforestation processes and reducing the volume harvested wood from forests and sustainability of harvesting processes. In this paper the results of an analysis of the effect of long-term residence of pine (Pinus sylvestris L.) and larch wood (Larix sibirica L.) stay in Arctic ice and seawater on the granulation of wood sawdust and the distribution of fine wood dust particles during the frame sawing process are presented. The distribution of wood chips and dust was analysed using sieve and laser diffraction methods. The results confirmed that Arctic driftwood, compared to normal wood for both analysed species, generate slightly more fine wood dust particles during the frame sawing process, which can be harmful to human health. However, these differences are not significant, indicating that the same dust extraction systems can be used for both sawing processes. • The particle size of larch driftwood dust is similar that of normal larch wood. • Increasing the feed per tooth increases the proportion of smaller particles. • The distribution of fine dust particles (<20 μm) is stronger in pine driftwood. • In the process of sawing driftwood, more the finest sawdust fractions were obtained. [ABSTRACT FROM AUTHOR]

The mechanical characteristics of wood members in a fire are reduced as a result of strength loss of the outermost charring layer and strength reduction of the secondary outer layer in high temperature zones. The charring layer has strong oxygen isolation effects. The main mechanical characteristics of larch wood, including modulus of elasticity (MOE), parallel-to-grain compressive (f c), tensile (f t), bending strengths (f b), and ductility coefficient, were determined under oxygen-free conditions at higher temperatures. Fourier transform-infrared (FT-IR) and scanning electron microscopies (SEM) were used to analyze chemical composition and microscopic changes of wood. The results suggested that hemicellulose softening resulted in decreases in mechanical properties of wood between 20 and 70 °C. From 70 to 190 °C, FT-IR spectroscopy provided evidence that increases in MOE and f c , with relatively minor changes in f b and f t , were associated with cellulose crystallinity and lignin cross-linking/condensation. The use of SEM further indicated degradation of wood composition. • Nitrogen environment was utilized to replicate the oxygen-free working environment of heated wood in a fire. • The chemical composition and microscopic changes at high temperatures were measured. • Strength variations were ascribed to chemical compositional degradation brought on by heat. • The loss of wood strength is more significantly impacted by high temperature than by heating duration. • Larch's strength at high temperatures were determined. [ABSTRACT FROM AUTHOR]

• The influence of age of larch wood on its strength was determined. • The influence of worm damage on the fatigue life of the wood was estimated. • A model for wood density equivalent fatigue life was developed. • The dynamic properties of larch wood are more affected by the aging process than the static properties. In many cultural heritage buildings, structural members are made of wood. Over the years, wood is exposed to various biotic and abiotic degradation factors, including moisture oscillations, mechanical stress, and insect and fungal decay. In the present respective study, an experimental study on the fatigue life of 350 years old larch wood was carried out. The fatigue life of the old wood was compared to the fatigue life of the recent larch wood. A statistical model for the fatigue-life curves and their scatter was built for both kinds of wood. The model can consider different factors to the fatigue life, e.g. wood density, specimen orientation during loading, and extent of insect damage. An equivalent number of load cycles to failure was also defined, enabling a direct comparison of the fatigue life data for specimens with different wood densities or orientations during loading. From the results, it can be concluded that the proposed statistical model adequately describes the fatigue behaviour of both the old, insect-damaged wood and the recent larch wood. [ABSTRACT FROM AUTHOR]

Larch wood is known to be a challenging substrate for waterborne coatings on windows or claddings in exterior applications. In earlier studies the surface properties of larch heartwood were characterised with low pH-values and high content of arabinogalactan. A systematic variation of formulations with different combinations of binders and thickening additives was investigated regarding the sensitivity of the coating materials to high acidity and arabinogalactan. Panels of spruce wood were treated with low-pH buffer solutions and arabinogalactan solutions and after drying the coating materials were applied by spraying. Acetic acid and arabinogalactan solutions were added stepwise to wet samples of coating materials while pH-values and viscosity were measured. Different buffer capacities, changes in viscosity and qualities of film formation were observed depending on coating formulation. The selection of binder and thickening additives enables the formulation of coating materials with lower sensitivity to specific surface properties of larch wood and thus higher quality. [ABSTRACT FROM AUTHOR]