Your search resulted in 58 documents. Displaying 25 entries per page.
Statistical evaluation of 'micro-bending' samples for classification of wood attacking fungi
1992 - IRG/WP 92-1544
Micro-specimens from both hardwood and softwood were exposed to selected species of field isolated fungi. The strength reduction and weight loss caused by these fungi were determined. A statistical procedure was then developed to classify the fungi into brown-, white-rot, or non-decay fungal categories based on these data. The procedure reveals the extent of hazard a fungus poses to wood members. ...
B Goodell, Jing Liu, A Homola, J Jellison, J Shottafer
Some Experiences with Stake Tests at BAM Test Fields and in the BAM Fungus Cellar
Part 2: Comparison of Static and Dynamic Moduli of Elasticity (MOE)
2005 - IRG/WP 05-20320
In routine in-ground stake tests of wood preservatives at the BAM test field Horstwalde and in the BAM fungus cellar periodical determinations of both static moduli of elasticity (MOE) on the basis of bending tests and dynamic MOE on the basis of the vibration method were performed as a possible method for the assessment of fungal attack. As expected from other publications, the absolute values of...
M Grinda, S Göller
In-ground field test of scots pine (Pinus sylvestris L.) sapwood and heartwood
2004 - IRG/WP 04-30336
Scots pine (Pinus sylvestris L.) sapwood and heartwood stakes treated with CCA-C and creosote were tested for one- year in a field plot in Bartın region in Turkey.
Scots pine heartwood stakes had lower preservative retention than sapwood stakes. Bending strength of the stakes was decreased after impregnation and one-year field test. While the bending strength of untreated sapwood was 93....
H Sivrikaya, H Hafizoglu
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
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
Residual resistance in eucalypt poles according to the degree of sanity
1984 - IRG/WP 2225
A lot of 50 eucalypt poles presenting external deterioration by fungus was taken from service and tested. These poles were classified into five degrees of sanity according to evaluation criteria adopted by the IPT Wood Division. After being classified, they were tested with respect to their bending resistance, in order to gather information about their critical degree of sanity which may define th...
F C Geraldo, S Milano, S G De Sequeira
Alternatives to CCA-treated Pinus radiata as vineyard posts
2004 - IRG/WP 04-50212
An estimated 10 million trellis posts per year are used in Australian vineyards and about 75% of these are CCA-treated Pinus radiata. CCA-treated Pinus radiata posts are brittle and at times in short supply. Use of some products containing CCA is being restricted in Australia. Recently, plantation forestry has expanded rapidly for disposal of industrial and irrigation wastewater. Thinnings from th...
M Mollah, J Smith, K McCarthy, L J Cookson
Bending properties of wood after its decay with Coniophora puteana and subsequent modification with selected chemicals
1999 - IRG/WP 99-40146
Mechanical properties of wood are often decreased due to decay processes caused by biotic and/or abiotic factors. Damaged wooden elements (e.g. historical structures) can be reinforced by more methods, including their modification with convenient chemicals. This paper presents influences of selected chemicals on basic bending properties (modulus of elasticity - MOE, modulus of rupture - MOR) of so...
L Reinprecht, S Varinska
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
Durability of Wood/Plastic Composites Made From Parthenium species
2002 - IRG/WP 02-40225
Previous study indicated that the natural chemical constituents of the guayule plant (Parthenium argentatum) improved some durability properties of wood when it was treated with resin extracted from guayule. At present, there are about a dozen species of Parthenium growing in the North American continent. P. argentatum is the only species with harvestable amounts of the rubber latex. Other specie...
P Chow, F S Nakayama , J A Youngquist, J H Muehl, A M Krzysik
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
Studies and experiences of occurrence and development of soft rot in salt-treated poles of pine (Pinus sylvestris) installed in Swedish transmission lines in the years 1940-1945
1977 - IRG/WP 277
The present work describes the result of microscopic examinations of some 2,000 borings extracted from 20 to 23-year-old salt-treated poles (Scots pine) from the southern and central parts of Sweden. The purpose was to map out the occurrence of soft rot in Sweden and its influence on the mechanical strength of the poles as well as to contribute to the development of new and more satisfactory metho...
H Friis-Hansen
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
Influence of the content of organic matter of soil on the degradation of wood by soft rot fungi
1970 - IRG/WP 27
The degradation of wood specimen burried in the soil by soft rot fungi is influenced by a number of factors. These are in particular the water holding capacity, water content, content of organic matter, pH, content of mineral nutritive substances etc. The results of the interlaboratory tests, carried out within the IRG/WP let presume that the intensity of wood degradation occurs proportionally inv...
O Wälchli
Supply of wooden transmission and telephone poles in Tanzania: Problems and possible solutions
1987 - IRG/WP 3424
The eucalypts which have been used widely for utility poles for more than 30 years have dwindled remarkably from traditional supply areas. Consequently, pole-using authorities are considering importing poles from abroad. This alternative is considered unrealistic and costly. The aims of this paper are: - to dispel fears of pole scarcity and to show that an abundant resource of a variety of tree sp...
K K Murira, S A Diwani
Wood cement composites using spent CCA treated wood
1999 - IRG/WP 99-50126
The feasibility of using spent or out-of-service CCA treated wood as a component of wood/cement composites was evaluated. Cold pressed wood particle cement boards were made using CCA treated particles from a red pine (Pinus resinosa Ait.) pole removed from service and from untreated red pine wood from a new pole. Boards were manufactured using a range of wood to cement ratios and water to cement r...
Chen Huang, P A Cooper
Some Experiences with Stake Tests at BAM Test Fields and in the BAM Fungus Cellar
Part 1: Comparison of Results of Visual Assessments and Determinations of Static Moduli of Elasticity (MOE)
2005 - IRG/WP 05-20319
With examples of routine in-ground stake tests differences are shown in the performance of wood preservatives at the BAM test fields Lehre and Horstwalde and in the BAM fungus cellar. Signs of attack of micro-organisms were assessed visually according to EN 252. Periodical determinations of static moduli of elasticity (MOE) revealed the influence of the attack on the elastic properties of the wood...
M Grinda, S Göller
Moisture correction for ultrasonic MOE measurements above fibre saturation point in Scots pine sapwood
2006 - IRG/WP 06-20333
There is a high correlation between methods for dynamic modulus of elasticity (MOEdyn) and static modulus of elasticity (MOEstat). MOEdyn methods have been found sensitive to detect early stages of decay and may be seen as an option for non-destructive wood durability testing. As the MOEstat measurements do not change after reaching the fibre saturation point, the uncorrected MOEdyn data from ultr...
E Larnøy, G Alfredsen, H Militz
Effect of wood decay on the proportional limit of thin wood samples stressed in the bending mode
2006 - IRG/WP 06-20334
When using bending stiffness as a measure of wood decay it is advantageous to repeatedly test individual samples after they are exposed to decay fungi for varying periods of time. In order to obtain reliable results, variation in modulus of elasticity (MOE) values of the test samples that are repeatable bent to a given deflection must be considered. In this study it was shown that sound 3mm thick ...
G Li, D Nicholas, T Schultz
High-energy multiple impact (HEMI)-test – Part 1: A new tool for quality control of thermally modified timber
2006 - IRG/WP 06-20346
Thermal modification processes improve durability and dimensional stability of wood, but the strength properties, especially the dynamic ones, are compromised and need to be considered with respect to industrial quality control. Results from standard dynamic strength testing, such as impact bending tests, suffer from high variability, and therefore require a high number of replicates. To overcome ...
C Brischke, A O Rapp, C R Welzbacher
Bending Properties of Southern Pine Treated with Micronized Preservative Systems
2008 - IRG/WP 08-40414
This study indicates that treatment of southern pine with micronized copper systems have no
deleterious effect on the residual strength property values. No statistical differences between wood treated with micronized systems and water-treated controls were noted when means were compared using either Tukey’s test or S-N-K mean comparison tests. Using the more discriminating Least Squares anal...
H M Barnes, G B Lindsey, J Hill, M Pompeo, R Hodge
Cantilever bending test of furfurylated poles
2008 - IRG/WP 08-40424
Ten, 8 m long poles of Scots pine (Pinus sylvestris) were treated with furfuryl alcohol to a WPG of approximately 40 %. A bending test was performed according to the principles in the draft European standard for wooden poles, prEN 14229 - Structural timber - Wood Poles for overhead lines. The bending strength and stiffness (MOE) for the poles tested were compared to an earlier study by the Swedish Wood Preservation Committee. In the latter study untreated, CCA-treated, ammoniacal Cu-PCP treated and creosoted poles were tested in bending. These types of poles were considered not to differ in strength and stiffness. The results of the furfurylated poles fit well with the results from the previous study. The bending strength and MOE values obtained are compared to the upper and lower 95-percentile values of the results from the previous study and all poles treated with furfuryl alcohol fit within this interval.Thus, this study indicates that a treatment with furfuryl alcohol does not result in a decrease of strength or stiffness. Further testing with a larger population of poles is necessary in order to get a statistically reliable result. In addition to further demonstration of the durability, the
treatment process must be optimised to ensure full sapwood penetration and measures have to be taken to avoid the serious cracking observed in this trial before furfurylation can be considered for treatment of Pinus sylvestris poles.
R Ziethén, J Jermer, A Clang
Diagnosis of failures in wood beams from historical house in Banská Štiavnica – Relations between ultrasonic measurements and bending properties
2010 - IRG/WP 10-20437
Various degrees of rot and other damages in ceiling beams with dimensions of 6500-8800 x 160-200 x 240-310 mm (length x height x width) situated in one historical bourgeois house in the UNESCO town Banská Štiavnica, Slovakia were determined visually and by the PUNDIT-plus ultrasonic device. Subsequently, for seventeen of the most bio-damaged fir (Abies alba Mill.) beams chosen for exchange were ...
L Reinprecht, M Pánek
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
Hydrothermal modification for upgrading the durability properties of soft deciduous wood
2010 - IRG/WP 10-40494
To extend the application potentialities of soft deciduous wood, upgrading the durability properties, hydrothermal modification (HTM) of aspen alder and birch wood was investigated. The treatment was conducted in a multifunctional laboratory device WTT. In the previous cases it has been found that the treatment at 160oC improves the durability insufficiently. The modification at 180oC ensured a hi...
B Andersons, I Andersone, V Biziks, I Irbe, J Chirkova, E Sansonetti, J Grinins, H Militz