Your search resulted in 49 documents. Displaying 25 entries per page.
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of ...
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
A dynamic approach to assess the modulus of elasticity in wood decay testing
1998 - IRG/WP 98-20139
In this study, the changes in elastic behaviour and mass losses of different hardwood and softwood species exposed to decay in a laboratory soil tests were assessed. Wood decay was monitored using different assessment methods, namely: mass loss and changes in elastic behaviours (MOE) determination. Elastic changes were determined by static and dynamic methods, for the latter, acoustic technique wa...
L Machek, H Militz, R Sierra-Alvarez
Supercritical fluid treatment: Effects on bending strength of white spruce heartwood
1993 - IRG/WP 93-20008
The effects of supercritical carbon dioxide on wood strength were evaluated using white spruce heartwood, a species known to be especially susceptible to collapse during exposure to higher pressures. The effects of pressures of 2000 or 3600 psig and temperatures of 40 or 80°C were evaluated using 30 or 60 minute exposure periods. No significant differences were noted in modulus of rupture or modu...
S M Smith, J J Morrell, E Sahle-Demessie, K L Levien
Effects of heat treatment on modulus of elasticity of beech wood
2002 - IRG/WP 02-40222
Heat treatment is the oldest, simplest and cheapest method for reducing hygroscopicity of wood. The heat treatment protects wood against to biological organisms as well as giving
wood dimensional stabilization without damaging environment. The effects of heat treatment on modulus of elasticity (MOE) of beech wood (Fagus orientalis Lipsky) naturally grown and intensively used in forest products in...
S Yildiz, G Çolakoglu, Ü C Yildiz, E D Gezer, A Temiz
Evaluation of the natural durability and ultrasonic method for decay detection of some european hardwood and softwood species
2004 - IRG/WP 04-10537
This paper presents the first part of an investigation on the natural durability of mixed plywood made of durable and non durable plies from the following selected timbers : Cedrus atlantica, Cupressus sempervirens, Castanea sativa, Populus sp. I 214 and Fagus sylvatica.
In order to carry out this study, the natural durability of the massive wood used to manufacture the plywood panels was asses...
F Faraji, M-F Thévenon, B Thibaut
Standardization of CCA treated 45 hardwood species grown in Bangladesh for REB crossarms
1995 - IRG/WP 95-20059
Researches on 45 hardwood species grown in Bangladesh regarding density, moduli of rupture (MOR), colour and treatability of sapwood and heartwood, seasoning property and natural durability of heartwood revealed that both sapwood and heartwood of 17 species could be full cell pressure treated with CCA at impregnation pressure of 14-18 kg/cm² and only sapwood of rest 28 species could be pressure t...
A K Lahiry
Evaluation of bending strength by non-destructive methods of Ezomatzu with white pocket rot
1991 - IRG/WP 2371
The possibility of application of three non-destructive methods was examined for evaluation of bending strength of ezomatsu (Picea jezoensis CARR.) with white pocket rot. As non-destructive methods, the measurements of ultrasonic wave propagation time, impact-induced stress wave propagation time and penetration depth of pin of "PILODYN Wood Tester" were applied to compare with visual evaluation of...
T Tanaka
Biological and physical properties of phenolic-resin treated wood before and after natural weathering
1999 - IRG/WP 99-40132
Biological and physical properties of phenolic resin-treated particleboards, which were made from fast growing tress and agrowaste as raw materials, were evaluated before and after natural weathering in tropical climate. The particles were sprayed with a mixture of a low molecular weight phenol-formaldehyde resin (5.0, 7.5 and 10% loading) and the adhesive phenol resin (8% loading). Results with l...
S Yusuf, Y Sudiyani, H Kajita, Y Imamura, M Takahashi
Effect of post-treatment drying schedule on the modulus of elasticity of CCA-treated southern pine dimension stock using nondestructive methods
1987 - IRG/WP 3413
This paper describes the results from the nondestructive testing for modulus of elasticity (MOE) of southern pine (Pinus sp.) 2 x 6's treated with chromated copper arsenate and redried using three commercial kiln schedules. The data indicate that redrying CCA-treated southern pine dimension stock treated to above-ground retentions (4 kg/m³) has no deleterious effect on the MOE, regardles...
H M Barnes, S Moore
Relationship between the bending strength and the degree of termite attacks on western hemlock by Coptotermes formosanus Shiraki
1990 - IRG/WP 1434
For the examination of the relationship between the bending strength and the degree of termite attacks, Western Hemlock (Tsuga heterophylla Sarg.) was used. Sixty specimens (4.5 x 4.5 x 82 cm³) were attacked by termites at the culture room of Coptotermes formosanus Shiraki. The termites were introduced on the central parts (10 cm) of specimens. In the case of the 2 points loading, the bending mom...
K Suzuki, T Tanaka
Biodetioration and strength reductions in preservative treated aspen waferboard
1983 - IRG/WP 2195
Experimental aspen waferboards, bonded with liquid or powdered phenol formaldehyde resins and treated by various methods with a wide selection of preservatives, were tested for fungal resistance in accelerated laboratory trials. Mold growth on the surface as well as weight and strength losses due to the actions of decay fungi were determined. Testing of board strength after decay in high and moder...
E L Schmidt, H J Hall, R O Gertjejansen, R C De Groot
Laser incising of spruce lumber for improved preservative penetration
1991 - IRG/WP 3646
Red spruce heartwood specimens were incised using a range of laser beam power levels and pulse durations. The penetration of CCA through these holes into the wood was monitored after pressure treatment. In addition, green and dried spruce samples were incised using two patterns with incision densities of either 16.1 holes/in² or 21.3 holes/in². Following CCA pressure treatment the samples were t...
B Goodell, F A Kamke, Jing Liu
Bending strength of heat-treated spruce and pine timber
2002 - IRG/WP 02-40242
Heat-treatment of spruce (Picea abies) and pine (Pinus sylvestris) beams (45 x 145 mm) gave a reduction in bending strength of approximately 50%. The bending stiffness (modulus of elasticity) only decreased by 3.5%. Tests were carried out according to EN 408. Another effect of the heat-treatment was increased variation in bending strength. The 5th percentile value of the bending strength, the so c...
C Bengtsson, J Jermer, F Brem
Acoustic technique for assessing decay in preservative treated wood
1998 - IRG/WP 98-20138
This study investigated the suitability of vibration techniques to assess the performance of wood preservatives in ground contact. Small stakes (10 x 5 x 100 mm3) of treated and untreated Scots pine sapwood were exposed to decay in lab-scale terrestrial ecosystems. Tests were conducted using three different soils including a garden compost soil, and soils obtained from a test field and a conifer f...
L Machek, M-L Edlund, R Sierra-Alvarez, H Millitz
Correlation between modulus of elasticity, mass losses and FTIR spectra of copper treated decayed wood
2006 - IRG/WP 06-10580
The composition of copper-based preservatives will change from copper-chromium to copper-ethanolamine, due to environmental demands. The most important drawback of copper-impregnated wood is the presence of tolerant fungal organisms that have developed an ability to degrade such preserved wood. In order to elucidate these processes, specimens (0.5×1.0×15 cm) made of Norway spruce (Picea abies) w...
M Humar, B Bucar, F Pohleven
Material properties of acetylated beech plywood
2008 - IRG/WP 08-40425
The effect of acetylation process on dimensional stability and mechanical properties of plywood made by Oriental beech layers (Fagus orientalis Lipsky) were studied. The layers cut into sizes of 200×200×2 mm and acetylated in 120°C for 30 and 60 min.
Thickness swelling (TS%), water absorption (WA%) and anti-swelling¬ efficiency (ASE%) of specimens were measured. Mechanical properties (MOE, MO...
A Talaei
Mechanical and chemical properties of blue stained wood
2009 - IRG/WP 09-10686
Discoloration of wood is frequently caused by blue-staining fungi. In the previous researches there was general opinion that blue-stain fungi do not influence mechanical properties. On the other hand, there were some opposite results reported as well. In order to elucidate this issue, specimens made of Pinus sylvestris sapwood were exposed to two the most frequent and important blue stain fungi Au...
M Humar, V Vek, B Bučar
Effects of concentration and temperature of CCA and CCB on wood strength of Turkish fir (Abies bornmulleriana Mattf.)
2009 - IRG/WP 09-40450
The purpose of this study was to present evidence for the effects of concentration and temperature of solutions of water-borne preservatives (chromated copper arsenate, CCA and chromated copper boron, CCB) on the static bending properties (modulus of elasticity, MOE and modulus of rupture, MOR) of Turkish fir (Abies bornmulleriana Mattf.). Wood samples were mechanically tested after a mild full ce...
I Usta, M Hale
Repairing of wooden elements by beta-method using carbon, steel or beech rods
2010 - IRG/WP 10-40488
Presented paper is focused on repairing of wooden elements by Beta joints reinforced with carbon, steel or beech rods, and on comparing the efficiency of these joints with traditional carpentry joints. In model laboratory experiments have been determined the bending strength (fm) and the modulus of elasticity (E) of control or original elements (fm-Control; Eo) from Norway spruce (Picea abies Kars...
L Reinprecht
Natural durability of wood tested in different environments in Northern Europe
2011 - IRG/WP 11-10747
Moisture is often recognised as a key factor regarding the long time performance of wooden products, and one of the main challenges for timber products is to predict accurate service life in use class 3 (not covered above ground) and use class 4 (in soil or fresh water contact). A range of durability classification studies have been performed both in field and laboratory. But for several wood spec...
P O Flæte, G Alfredsen, F G Evans
Changes of fungicidal, mechanical and sorption properties of wood during above ground outdoor exposure
2013 - IRG/WP 13-20513
The aim of this preliminary study was to investigate differences in mechanical, fungicidal, and sorption properties of four different wood species (sweet chestnut (Castanea sativa), common beach (Fagus sylvatica), Norway spruce (Picea abies), and copper-ethanolamine (CuE) impregnated Norway spruce (Picea abies)) that were exposed in the 3rd use class (CEN, 1992) for periods between 4 and 30 months...
N Thaler, M Humar
Resistance of WPC against wood destroying fungi
2013 - IRG/WP 13-40627
The investigation of biological durability is a fundamental topic to assess the performance of Wood Plastic Composites (WPC) particularly for outdoor applications. In the last years, different test setups based on existing standards on the field of wood as well as the field of plastics were used for WPC. But the test methodologies give different information about the durability of the tested mater...
A Gellerich, S Bollmus, A Krause
Combined effects of thermal modification and ACQ-D impregnation on properties of southern yellow pine wood
2013 - IRG/WP 13-40637
In this study, samples of southern yellow pine sapwood were first thermally modified and then treated by the alkaline copper quat-type D (ACQ-D) wood preservative. Two heating temperature (180℃ and 220℃) and two concentrations of ACQ-D solution (0.9% and 1.35%) were used in the experiments. The combined effects of thermal modification and ACQ-D on leaching performance, mechanical prope...
Wang Wang, Yuan Zhu, Jinzhen Cao
Influence of weathering on the mechanical properties and performance of exterior wood coatings
2022 - IRG/WP 22-40951
Three commercial coatings were exposed to artificial (EN 927-6) and natural weathering (EN 927-3) on wood samples. Cracking was visually assessed as well as Persoz hardness. Free films of the same coatings were also exposed to the same weathering tests before their tensile properties were measured. Results show that artificial and natural weathering modified the overall mechanical properties of wo...
L Podgorski, J-D Lanvin