Your search resulted in 662 documents. Displaying 25 entries per page.
Is laboratory testing of decay resistance questionable as a single criterion for natural durability?
1996 - IRG/WP 96-20096
In a laboratory test set up over 20 hardwood species were evaluated according to the European Standard EN 350-1 including Basidiomycete and soft rot testing. Half of the species used were of a known natural durability. The Basidiomycete testing was carried out using Coriolus versicolor, Gloeophyllum trabeum and Coniophora puteana in a malt agar test similar to EN 113. From this test it was not pos...
J Van Acker, M Stevens, T Van Cauwenberghe, T Seynaeve
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
Chemical treatment of ten Amazonian timber species of low natural durability
1991 - IRG/WP 3640
The objective of this work was to evaluate the performance of 10 amazonian wood species of low natural durability, to treatment with CCA preservative (2% concentration): it was concluded that all species studied are easily treated with this preservative. The sapwood showed high absorption and total penetration. The heartwood is relatively easy to preserve, exception to Parkia nitidae (Fava), Quale...
C S Neta, B F Vianez
Assessment of untreated Papua New Guinea timbers against subterranean termites. Final report
1993 - IRG/WP 93-10041
Four years after the exposure of eight timber species of varying density against subterranean termites in a field trial, Kwila was still generally sound while Taun, Malas and PNG Walnut were beginning to be attacked slightly to moderately. Calophyllum, Kamarere, PNG Beech and White Cheesewood were severely attacked and failed. Results after the period of exposure shows that Kwila rates highly as t...
H C Konabe, M Rokova
Laboratory tests on the natural durability of timber methods and problems
1984 - IRG/WP 2217
In literature a large variety of test methods is mentioned to examine the natural resistance of timber against fungal attack. This concerns the kind of sampling as well as the test procedure, the test fungi, the duration of test, and the classification of the resistance according to the test results. These variations, however, are of great influence on the test result. Long term exposure will lead...
H Willeitner
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 1: Optimisation of the extraction conditions
2000 - IRG/WP 00-30238
As the first phase of a large project aimed at recovering 'waste' durability components from sawmill residues of Callitris glaucophylla, several solvents and extraction methods were evaluated, initially in the laboratory and then at pilot industrial scale. Extracts were compared by crude total dissolved solids content, by chemical analysis using GC-MS and LC-MS, and by laboratory...
M J Kennedy, Hui Jiang, L M Stephens
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
Utilization of coconut timber from north Sulawesi, Indonesia. Part 1: Durability
1994 - IRG/WP 94-30044
Coconut timber from non-productive plantations is a byproduct of an agricultural crop and, by the same token, constitutes a renewable resource which may serve as a complement to or, at least in part, as a substitute for traditional timbers in local markets. Its more extensive utilization is expected to contribute to the conservation of tropical rain forests. Export of coconut timber and/or wood pr...
R-D Peek
Comparative natural resistance of eighty-two timber species to damage by marine borers at Goa (India)
1996 - IRG/WP 96-10139
Natural bioresistance of eighty-two species of Indian timbers to attack by marine wood-borers has been presented based on data collected from test panels exposed in Goa waters (west coast of India) for periods ranging from five to thirteen months. All the timber species, except Artocarpus gomeziana and Pterocarpus santalinus, were completely destroyed within a short period of three to six months. ...
L N Santhakumaran
A study of poplar LVL durability improvement:
1999 - IRG/WP 99-40148
The aim of this study was to optimise the durability of LVL panels by adding boron during the gluing process. Poplar veneers (2,6 mm thickness ) were selected by ISORY a French company . Two types of glue were tested : Phenol resorcine and Melamine Urea Formaldehyde. Each of them was mixed with various concentrations of borax (for the first one) and Boric acid(for the second one). Mechanical prope...
B Charrier, V Bridaux, N Fauroux, F Charrier
Termite resistance of Malaysian and exotic woods with plantation potential: Field evaluation
1998 - IRG/WP 98-10289
An in-ground resistance of selected Malaysian and exotic timbers to attack by a representative aggressive subterranean Coptotermes termite was evaluated as part of an on-going collaborative research between the Forest Research Institute of Malaysia and the University of Hawaii on termite control of building timbers under humid tropical conditions. A test site at FRIM, highly susceptible to the sub...
A H H Wong, J K Grace, L H Kirton
Field evaluation of the above-ground susceptibility of Pinus heartwood and untreated or treated sapwood to two species of Australian subterranean termites
1996 - IRG/WP 96-10147
Plantation-grown Pinus elliottii, Pinus caribaea and Pinus radiata specimens containing heartwood and untreated or preservative-treated sapwood were exposed above ground to the subterranean termites Coptotermes acinaciformis or Mastotermes darwiniensis near Sydney (NSW), Brisbane and Townsville (Qld), and Darwin (NT), using a variety of exposure techniques. Heartwood of Pinus elliottii and Pinus c...
M J Kennedy, J W Creffield, R H Eldridge, B C Peters
Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the...
C Brischke, A O Rapp
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
Preservative treatment of common timbers and bamboos of Bangladesh for rural electrification infrastructure
1998 - IRG/WP 98-40104
Researches revealed new treatment grades, treatment groups, grading groups, natural durability grades, strength groups and a new preservative combination for remedial treatment and sterilization of most common timbers and bamboos of Bangladesh. The obtained findings are applicable for equivalent timber species having equivalent climatic condition. Sapwoods are always perishable and timbers with wh...
A K Lahiry
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
Introducing bamboos for their importance and conservation
2005 - IRG/WP 05-10546
Bamboo is a socio-economically, industrially and environmentally important forest and rural crop in Asia. It is an essential task for the people in this region to conserve the bamboos and preserve the bamboo products for their sustainable continuity. An earnest need for this task is to introduce a variety of important information on bamboos. In this research paper the botanical position, distribut...
A K Lahiry