Your search resulted in 3272 documents. Displaying 25 entries per page.
The influence of the location of a wood defect on the modulus of elasticity determination in wood durability testing
2004 - IRG/WP 04-20287
This study investigates the influence of the location of a wood failure in stakes upon elastic changes observed in beech specimens with the resonance vibration technique. Natural failures were simulated by artificially created defects at different locations of the test stake. The results indicate that the location of an attack in a stake is important for the measurement outcome. When the attack is...
L Machek, H Militz
Durability of exterior natural wood finishes in Brazil
1985 - IRG/WP 3343
Wood finishes systems were evaluated in natural weathering conditions during 5 (five) years, over "Parana-pine" (Araucaria angustifolia). Test samples results show that: - Semitransparent wood preservative stains, based on polimerized linseed oil, provided very good protection to the wood, compared with the one based on alkyd varnish; - Solid color wood preservative stains provided good durability...
D R Macedo
Natural durability of fifty species of Indian timber in Goa waters against marine wood-borers
1989 - IRG/WP 4150
Results of the investigations on the natural durabilitv of fifty species of Indian timber, based on data collected bv exposing test panels at Betim near Panaji (Goa) continuously for a period of 11 months are presented. The study revealed that none of the timber species tested has any natural resistance at this locality and all the panels were completely destroyed within 11 months. Details on the ...
L N Santhakumaran, S Udaya Bhaskar, J C Jain
A comparison between different accelerated test methods for the determination of the natural durability of wood
1996 - IRG/WP 96-20099
According to the European standard EN 350-1 the natural durability of wood is defined as: "the inherent resistance of wood to attack by wood destroying organisms". This standard also describes how, for certain hazard classes, the durability is determined. The two methods described in this standard are the kolleflask method (EN 113) and the field-stake-test method (EN 252). The EN 113 test gives re...
H Militz, S G L Michon, J E Polman, M Stevens
NIR spectroscopy for rapid estimation of decay resistance
2004 - IRG/WP 04-20294
In Scandinavia Scots pine (Pinus sylvestris L.) is an important commercial tree species. Its heartwood has traditionally been used in constructions exposed to risk of decay. In a laboratory experiment Scots pine wood specimens sampled from inner heartwood, outer heartwood and sapwood were exposed to the brown rot fungus Poria placenta. In general outer heartwood was more resistant than inner heart...
P O Flæte, E Ystrøm Haartveit
Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions...
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek
Variation of natural durability of sugi (Cryptomeria japonica) wood in 15 clones examined by decay test (Preliminary report)
2004 - IRG/WP 04-10526
Natural durability of wood in 27 trees from 15 clones of sugi (Cryptomeria japonica)　 was investigated by an accelerated decay test. Thirty years old trees were collected from a clonal trial in Ibaraki prefecture, Japan. Natural durability is usually evaluated in heartwood. Mass losses of heartwood caused by a brown rot decay fungus, Fomitopsis palustris and a white rot decay fungus, Py...
K Yamamoto, A Tamura, R Nakada
Moisture content development in lap-joints of different wood species in outside exposure trials
1998 - IRG/WP 98-20143
Lap-joint trails (following European Standard EN 12037) were set up with 11 different softwood and hardwood species. Half of the number of the lap-joint specimens were coated with an alkyd coating. The moisture development has been followed during a 19 months period. In this paper, the out comes of different moisture contents evaluations are presented. The results show, that the moisture content o...
H Militz, M Broertjes, C J Bloom
The comparative resistance to fungi of the wood munika (Pinus heldreichii Christ.), fir (Abies alba Mill.) and spruce (Picea excelsa Poir.) compared with Pinus sylvestris L. and some physical and mechanical characteristics of munika
1981 - IRG/WP 1129
The munika (Pinus heldreichii Christ.) is situated primarily in the Balkans, and partially in the south of the Apenine peninsula. As an endemic species, with a very little annual increment, it has not been used enough as a timber for mechanical conversion up till now, although the oldest trees can grow to 27 m in height, with a diameter at breast height of about 60 cm. According to data of many Ba...
M Petrovic, M Miric
Natural durability of Norwegian wood species for above ground applications – Project presentation and preliminary results
2006 - IRG/WP 06-10594
In Norway exterior wood structures have traditionally nearly exclusively been made of treated and untreated Norway spruce (Picea abies (L.) Karst) and Scots pine (Pinus sylvestris L.). In recent years there has been a tendency that other tree species, like various domestic hardwoods and imported species have been used in exterior above ground applications, often unfinished. For several wood speci...
P O Flæte, G Alfredsen, F G Evans
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
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 4: Analysis of extracts and treated wood for active components
2000 - IRG/WP 00-20215
In order to facilitate the commercial implementation of a large project aimed at recovering 'waste' durability components from sawmill residues of Callitris glaucophylla, it has been essential to develop analytical methodology for the important bioactive components of the heartwood extract. This methodology will be used 1) to standardise the activity of successive production batc...
Hui Jiang, M J Kennedy, L M Stephens
Evaluating the resistance of wood-based panel products to fungal attack
1995 - IRG/WP 95-20071
At present there is considerable disagreement among national research institutes within Europe and panel product manufacturers on the most appropriate method of testing and indeed the need for specific biological durability testing. This paper seeks to place before a broader international audience, the issues related to development of a European standard for evaluating the resistance to fungal dec...
R G Lea, R W Berry
The effect of alternative pre-conditioning procedures on the durability of wood based board materials to decay fungi
1997 - IRG/WP 97-20105
In the biological testing of wood based board materials it has been shown that exposure of boards in a closed vessel system may lead to inaccurate results due to the build up of volatile substances that inhibit the test fungi. It is thought that this is a transitory effect of freshly manufactured boards. In the European standard for testing fungal durability of board materials which is currently u...
S F Curling, R J Murphy, J K Carey
Durability aspects of (hydro)thermal treated wood
2000 - IRG/WP 00-40160
Samples of several wood species were treated in a two steps process, subsequently hydrothermal and dry heat-treated, by the so-called PLATO-process and analysed for their resistance against fungal attack. Both PLATO-treated and dry heat-treated specimen were prepared and analysed, in order to study the influence of moisture during hydrothermal treatment of wood. The resistance against all of the s...
B F Tjeerdsma, M Stevens, H Militz
The improvement of wood durability by retification process
1993 - IRG/WP 93-40015
A material with new properties is obtained by retification process. It consists of a light pyrolysis of wood which becomes more stable and especially more resistant to fungal attack with few decrease of mechanical properties. Tests were carried out on three susceptible wood species (Poplar, Spruce, Fir) that are used in construction and are difficult to treat with wood preservatives. Retified wood...
D Dirol, R Guyonnet
Improvement of intrinsic properties of wood by chemical wood densification - Hydrophobic aspects and durability aspects
1999 - IRG/WP 99-40149
To improve the intrinsic properties of Scot pine wood ((1) hydrophobic surface and (2) durability), two ways of chemical modification have been tested. The first one is the chemical modification of hydroxyl groups by active substances like diisocyanate compounds with a copolymerization step. The second way is a densification by an impregnation of resins and a gamma polymerisation. This second way ...
G Labat, Q K Tran, I Le Bayon
Relative merits of laboratory and field tests for assessing wood decay resistance
1993 - IRG/WP 93-20009
Laboratory and field trials have long been employed for assessing natural durability of a variety of wood species, but there is a continuing debate concerning the relative merits of approach. While laboratory tests provide carefully controlled conditions for decay, they are often criticized for being too artificial to produce meaningful results. Conversely, field trials often vary widely between t...
T C Scheffer, J J Morrell
Some studies on fungal deterioration of rubber wood (Hevea brasiliensis)
1980 - IRG/WP 2140
For the sreening of anti-stain chemicals trials with selected agricultural fungicides and new chemicals were carried out. Botryodiplodia theobromae, Aspergillus sp. and Penicillium sp. were used at test organisms. For testing the durability of rubber wood (Hevea brasiliensis) suitable local rotting fungi (Basidiomycetes), based on high degrading power, which may later be employed in standard tests...
A Sujan, A G Tan, M Stevens
Preliminary studies of the performance of iron chelators as inhibitors of brown rot (Coniophora puteana) attack
1996 - IRG/WP 96-10185
This paper describes experiments to examine the proposal that the presence of iron is essential for brown rot fungi to utilize hydroxyl radicals remote from the hyphae as a means of converting the wood into a food source. reliminary test results are presented from trials using three different iron chelators impregnated into Scots pine (Pinus sylvestris) sapwood blocks. Their relative effects on th...
E D Suttie, R J Orsler, P M Wood
Wood kiln drying. Simple process of material treament or soft method of preservation? (Le séchage arificiel du bois. Simple opération de traitement du metériau ou méthode douce de préservation?)
1993 - IRG/WP 93-50001-14
Among the processes enabling to extend wood durability, kiln drying can be considered as a treatment and soft preservation method. Dry woods are naturally durable provided they are not subject to important retaking of the moisture. Drying thanks to the application of temperatures from 50 to120°C enable to execute a thermic treatment which kills grubs and mushrooms to ensure a sterilization that c...
F More-Chevalier
Field Trials with mini-stakes
2002 - IRG/WP 02-20244
In 1995 an extensive field test program with wood mini-stakes, 8 x 20 x 200 mm, was started. In these trials a large number of parameters are being evaluated, including several new wood preservatives, differently chemically modified woods and natural durability of various wood species. The test sites are three fields in Sweden for in-ground and “close to ground” testing, one subterranean termi...
M Westin, A O Rapp, Y S Hadi, T Nilsson
Chitosan for wood protection - state of the art
2005 - IRG/WP 05-30378
The aim of this paper was to give a state of the art description of chitosan as a wood protecting agent. Chitosan is a metal free natural compound derived from crustacean shells and is under evaluation as an environmentally benign wood protecting agent. Information from journals states that chitosan may act both fungistatically and at higher concentrations, as fungitoxic, but the mode of action is...
M Eikenes, G Alfredsen, E Larnøy, H Militz, B Kreber, C Chittenden
Evaluation of teak sawdayst Tectona grandis L Fil as a potential source to obtain a natural wood preservative in Colombia
2004 - IRG/WP 04-30356
Plantation Teak (Tectona grandis L. Fil) has been tested as a possible source of natural wood preservatives due to the known excellent durability of old-growth teak wood. Field tests (ground proximity termite and above ground simulated decking exposures) were established in Colombia in April 2003 at two different test sites with different climates (Tropical Dry and Rain forest). Teak heartwood ex...
A Castillo, Y Cabrera, A F Preston, R Morris