Natural durability of some wood species in ground contact at four sites in Turkey, part 2: the mechanical properties

In this study, heartwood, sapwood and copper-chromium-boron (CCB) impregnated sapwood samples of various tree species, including Scotch pine (Pinus sylvestris L), Caucasian spruce (Picea orientalis (L.) Peterm), European beech (Fagus orientalis L.) and common alder (Alnus glutinosa subsp. barbata), with dimensions of 20x20x300 mm, were investigated. These samples were subjected to soil contact, specifically under conditions of hazard class 4 according to EN 252, for a period of 3 years. The study was conducted in four different provinces of Turkey, namely Trabzon, Muğla, Çanakkale and Elazığ, each of which is characterized by different climatic conditions. The climatic index and soil structures of the sites were studied. The visual decay, weight loss and density values of the samples collected from the test sites were evaluated. Elazığ had the lowest visual decay rate, the lowest weight loss and the highest density. More negative values were observed in Çanakkale, Muğla and Trabzon. In terms of climate type, it can be said that the Scotch pine and Caucasian spruce wood samples have higher resistance than the European beech and common alder samples. In particular, the heartwood of conifers was found to be more durable than the sapwood. In addition, no deformation was observed in any of the impregnated wood samples. All impregnated wood samples showed very good durability.

The aim of this study was to investigate the effects of impregnation with Imersol‐Aqua (I‐AQUA) on the modulus of elasticity in bending of some woods. For our study, Oriental beech (Fagus orientalis Lipsky), oak (Quercus petrea Liebl.), Scotch pine (Pinus sylvestris Lipsky), Uludağ fir (Abies Bornmülleriana Lipsky), Oriental spruce (Picea orientalis Lipsky), and poplar (Populus nigra L.) wood samples were prepared according to TS EN (Turkish Standards; European Norm) 408 and impregnated with I‐AQUA by the method of short‐, medium‐, and long‐term dipping according to ASTM D 1413 and producers' definition. After the impregnation process, modulus of elasticity was measured according to TS EN 408. Consequently, among the nonimpregnated wood samples, modulus of elasticity was found to be the highest in Oriental beech (Fagus orientalis Lipsky), (12,490 N mm−2) and the lowest in poplar (5439 N mm−2). As for the period of dipping, the highest modulus of elasticity was obtained in short‐term dipping and the lowest in long‐term dipping. Considering the interaction of wood type and period of impregnation, the highest modulus of elasticity in bending was obtained in Oriental beech (Fagus orientalis Lipsky) with short‐term dipping (10,720 N mm−2) whereas the lowest was in poplar with long‐term dipping (4597 N mm−2). In consequence, in massive constructions and furniture elements where the modulus of elasticity in bending after impregnation is of great concern, short term impregnation of Oriental beech and Scotch pine materials could be recommended. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3210–3217, 2006

Effects of impregnation with Imersol-AQUA on the bending strength of some wood materials

Adaptations ofAbies nordmanniana, Picea orientalis, Pinus sylvestris, Fagus orientalis, and Carpinus betulusto the abiotic environmental conditions of the study area largely determined their predicted distribution in the Caucasus. The ecological niches of the species mostly coincided in two analyzed complex environmental factors (characteristics of water regime and topographic parameters). The complex humidity factor was the main factor determining the potential distribution the forest-forming species in the Caucasus (65% of the contribution in the Maxent models). Topographic ENVIREM predictors were also significant in the species distribution (20% of the contribution in the models).Abies nordmannianaandFagus orientaliswere the most sensitive to the humidity factor, whilePinus sylvestrisdepended largely on the topographic factors. The similarity of the distribution potential of the studied species in the Caucasus was explained largely by a high degree of overlap of ecological niches (Schoener’s D = 0.55-0.79) and their visual overlap in the orthogonal space of the analyzed ecological factors. The largest Schoener’s D indexes were observed for the pairsPinus sylvestris–Picea orientalis,Abies nordmanniana–Picea orientalis,Fagus orientalis–Picea orientalis, andFagus orientalis–Carpinus betulus.Carpinus betulus,Fagus orientalisandPinus sylvestrishad the widest ecological niches.

A direct comparison of the radial growth response to drought of European and Oriental beech

Effects of impregnation with Imersol-aqua on the modulus of elasticity in bending of laminated wood materials

This study has been performed to determine the effects of impregnation with fire retardant chemical materials on the modulus of elasticity (MOE) in bending of Oriental beech, European oak and Scotch pine wood materials. To achieve this goal, test samples prepared from woods of Oriental beech, European oak and Scotch pine according to TS EN 345 regulations were impregnated with ammonium-sulfate [(NH 4 ) 2 S0 4 ], sodium acetate (NaC 2 H3O 2 3H 2 O), aluminum chloride (Al 2 C 6 I 2 H 2 O), borax [Na 2 B 4 O 7 5H 2 O], boric acid [H 3. BO 3 ] and, borax + boric acid (w:w= %50:50). The modulus of elasticity in bending of impregnated wood samples were determined according to TS EN 408. Consequently, according to wood species; modulus of elasticity in bending was found the highest value at beech (10350 N/mm 2 ) and the lowest value at pine wood (9501 N/mm 2 ). According to variety of impregnation; modulus of elasticity in bending values were found no statistical difference ​​ between control samples and impregnated test samples. Considering the interaction of wood type and process; modulus of elasticity in bending was found the highest value at beech + borax (11450 N/mm 2 ) and the lowest value at pine + control samples (8223 N/mm 2 ). As a result, in the massive construction and furniture elements that the modulus of elasticity in bending after the impregnation with borax is of great concern, Oriental beech wood materials could be recommended.

Aim of study: In this study, natural durability of some domestic and foreign wood species against Hylotrupes bajulus and Anobium punctatum larvae were tested on laboratory scaleArea of study: This study was conducted at Department of Forest Products Engineering in Duzce University, Turkey and Federal Institute for Materials Research and Testing (BAM), Germany.Material and Methods: Scotch pine (Pinus sylvestris), fir (Abies nordmanniana), spruce (Picea orientalis), cedar (Cedrus libani), poplar (Populus tremula) and beech (Fagus orientalis) woods were used to test H. bajulus larvae (EN 46-1). Alder (Alnus glutinosa), oak (Quercus cerris), poplar (Populus tremula), beech (Fagus orientalis), maple (Acer carpinifolium), ash (Fraxinus angustifolia), teak (Tectona grandis), ayous (Triplochiton scleroxylon), movingui (Distemonanthus benthamianus), dahoma (Piptadeniastrum africanum), iroko (Chlorophora excelsa), bubinga (Guibourtia tessmannii) and sapele (Entandrophragma cylindiricum) woods were used for A. punctatum larvae (EN 49-1). At the end of the experiment, the mortality rates of the larvae were determined and the size and weights of the surviving larvae were measured.Main results: F. orientalis and C. libani were found to be the most resistant wood species against H. bajulus larvae while A. nordmanniana was the least resistant. All tropical wood species and oak and maple from domestic wood species showed 100% mortality rate therefore found to be the most resistant against A. punctatum larvae. The most vulnerable wood species was found to be alder with a 35% mortality. Research highlights: while F. orientalis, C. libani, and P. tremula were found the most resistance wood species against H. bajulus, P. sylvestris and A. nordmanniana were determined as most vulnerable. All tropical wood species and two domestic species (Q. cerris and A. carpinifolium) showed the highest mortality rate as 100%. The least durable domestic wood was determined as alder.

Impacts of impregnation with Imersol-Aqua on the compression strength of some solid wood materials

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The present study examined the bending moment capacity and rigidity of T-type out-of-plane furniture joints and investigated the effects of heat treatment, wood species, and joint type factors on these joints. Heat treatment method clearly decreased the modulus of rupture (MOR) and the modulus of elasticity (MOE) of selected wood species. The bending strength of wood samples was reduced after the heat treatment, decreasing with increased loss of mass. For the heat-treated T-type joints, maximum bending strength values were obtained with Iroko (Chlorophora excelsa) for both mortise and tenon (MT) joints and blind MT (BMT) joints. The lowest reduction in bending strength was observed in Ash (Fraxinus excelsior L.) constructed with MT joints and with BMT joints. In general, the BMT joint had higher bending strength than MT joints. The best rigidity constant (7.21) was obtained with control Iroko BMT joints, while the worst rigidity constant (15.10) was obtained with control Oriental spruce (Picea orientalis L.) MT joints. In terms of heat-treated samples, the best rigidity constant (7.59) was obtained with Black pine (Pinus nigra L.) MT joints, while the worst rigidity constant (14.01) was obtained with Oriental spruce BMT joints. The maximum performance in joint stiffness was determined for Iroko sample BMT joints and Iroko MT joints. Lowest reduction in joint stiffness was observed in Scotch pine MT joints and Ash BMT joints. Heat treatment, wood type, and joint type had a significant effect on the bending strength of T-type MT post-rail joints. BMT joints produced from heat-treated Iroko wood can be considered as the most durable T-type joint for outdoor sitting furniture construction.

Moisture content (MC) is one of the most important factors that can affect many physical and mechanical properties of wood and veneers. MC strongly affects the final strength and durability of joints, development of surface checks in the wood and dimensional stability of the bonded assembly. In this study, plywood panels made from Alnus glutinosa (Alder), Fagus orientalis (Beech) and Picea orientalis (Spruce) wood veneers were treated with ammonium acetate, borax and boric acid by using dipping method to test for their equilibrium moisture content (EMC). Borax and boric acid solutions were used for fire-retardancy, and ammonium acetate for reducing formaldehyde emission. Two different veneer drying temperatures (20°C and 180°C) were used to reveal the effects of veneer drying at high temperature on the hygroscopicity of plywood panels. EMC values of alder, beech and spruce panels decreased significantly with veneer drying at high temperature. Picea orientalis (Spruce) plywood panels had the highest EMC values and followed by Alnus glutinosa (Alder) and Fagus orientalis (Beech) panels. EMC values of plywood panels increased significantly for both drying temperatures after ammonium acetate, borax and boric acid treatments.

This study has been performed for determining the effects of impregnation with Timbercare Aqua (Tc) on the red and yellow color tone of some woods and varnishes. For this purpose, the test samples prepared from Oriental beech, European oak, Scotch pine, Oriental spruce, and Uludag fir woods, which met the requirements of ASTM D 358, was impregnated with Tc according to ASTM D 1413 and producer's definition. After impregnation, wood surfaces have been coated by Sayerlack parquet varnish (Sp), Sayerlack interior varnish (Si), and Sayerlack exterior varnish (Se) varnishes in accordance with the ASTM D 3023 standards. According to ASTM D 2244, the red and yellow color tone of samples after varnishing process was determined. As a result, the value of red color tone was the highest in Oriental beech (15.21) and the lowest in Uludag fir (5.38). For the wood material, impregnation material, and varnish interaction, the red color tone value was the highest in Oriental beech + Tc + Sp (18.43) and the lowest in Uludag fir + Tc + Si (3.92). The value of the yellow color tone was the highest in pine (34.45) and the lowest in Oriental beech (26.50). For the wood material, impregnation material, and varnish interaction, the yellow color tone value was the highest in Oriental spruce + Tc + Sp (42.12) and the lowest in Oriental beech + Tc + Si (21.47). This effect may be due to the impacts of impregnation chemical on wood extractives and color pigments in varnish. Accordingly, it should be taken into care for applications where the red and yellow color tone value is important. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Structural performance of the finger-jointed strength of some wood species with different joint configurations

The wood fiber dimensions (fiber length, fiber width, cell wall thickness and lumen diameter), physical (oven-dry density) and mechanical properties (modulus of rupture, modulus of elasticity, compression parallel to the grain) of five hardwood plants such as oak ( Quercus castaneaefolia ), beech ( Fagus orientalis ), hornbeam ( Carpinus betulus ), alder ( Alnus glutinosa ) and ash ( Fraxinus excelsior ) were investigated. These trees are important plant species for wood production in Iran. Five normal trees of each plant species were selected in north part of Iran and log samples were cut between 2-4 m of stem height to determine the mentioned properties. The relationship between physical properties (wood density) and anatomical characteristics with mechanical strength traits were determined by Pearson correlation. Results of analysis of variance (ANOVA) indicated that the types of plant species had significant effect on the different wood properties. The highest of wood density, modulus of rupture, modulus of elasticity and compression parallel to the grain values were found in hornbeam, beech, ash, and oak, respectively. The lowest of mechanical strength properties was found in alder wood.