Your search resulted in 512 documents. Displaying 25 entries per page.
Natural Durability Classification Systems Used Around the World
2009 - IRG/WP 09-10694
Around the world natural durability is classified in different ways. The nature and rigor of the tests used to measure durability, the method of classification based on these data, and use of these classifications to specify end uses or predict service life all vary. This can lead to confusion among people not familiar with the various systems used. This review describes the methods used to classi...
R Stirling
Adequate preservative treatment of tropical and subtropical hardwoods for electric anchor logs
1997 - IRG/WP 97-40101
Most available 27 different hardwood species grown in Bangladesh was investigated regarding suitability as CCA-C (chromated copper arsenate type-C) impregnated anchor logs for rural electrification programme. The kiln-drying properties, sapwood thicknesses, CCA treatability grades of sapwood and heartwood, natural durability of heartwood and CCA retainability at specific assay zone separated 27 ha...
A K Lahiry
Natural durability of some commercial timbers of Sarawak, Malaysia in tropical marine environment
2005 - IRG/WP 05-10561
The abundant supply of timber resources in Sarawak makes timber an ideal choice to be used for marine construction. The natural durability of the main commercial timber species of Sarawak in ground contact is well established but the same is not available for marine environment.
This study was conducted to assess the natural durability of 28 commercial timber species in tropical marine environmen...
K Jenang, Wang Choon Ling
Natural durability of some common Indian timbers and marine plywood against biodeterioration in Kochi waters (India)
1992 - IRG/WP 92-4177
Panels of thirty-eight timber species and marine plywood were tested in Kochi harbour (South-west India) for periods ranging from 3 to 21 months, so as to evaluate their natural resistance against marine borers. Results indicate that all the timber species studied are non-durable, 6 of them having undergone more than 50% internal destruction within 3 months; 14 species in 6 months, 13 species and ...
L N Santhakumaran, M V Rao
Criteria for basidiomycetes testing and ways of defining natural durability classes
1998 - IRG/WP 98-20144
Within the framework of a European research project several laboratories have tested a series of 17 wood species covering the total range of natural durability.
Basidiomycete tests are part of the total set up. Although generally based upon standard methods some minor differences in execution of the tests were evaluated for their impact on the results. This variation was superimposed with the fac...
J Van Acker, M Stevens, J K Carey, R Sierra-Alvarez, H Militz, I Le Bayon, G Kleist, R-D Peek
Natural durability of eight tropical hardwoods species from Africa
2005 - IRG/WP 05-10563
Current forest inventory results reveal that there are more than 700 hundred-hardwood species in tropical forests, of which less than 10 percent are harvested and used for commercial purposes. The increased use of lesser-known species can decrease the pressure on current commercial species, increase the value of the forest and lead to better management practices. However basic information on physi...
P Nzokou, K Wehner, D P Kamdem
Influence of a dipping preservative treatment on the performance of wood finished with waterborne coatings
1998 - IRG/WP 98-40121
Within a larger European research project on the performance of joinery finished with waterborne coatings, the influence of a water based dipping preservative treatment was studied in several ways. Six different waterborne coatings were tested with and without a preservative underneath the coating. The performance was tested on pine sapwood and spruce panels in a 2-year outdoor weathering trial on...
M De Meijer, J Creemers, W Cobben, P Ahola
Evaluating the natural durability of a number of lesser known species of Ghanaian hardwoods using a short term laboratory assay
2004 - IRG/WP 04-10540
Resistance of a number of Ghanaian hardwoods to attack by the crustacean Limnoria quadripunctata was assessed by measuring the production of faecal pellets under forced feeding conditions over a two week period. Small sticks of commercially available, lesser known timber species, were leached in seawater for one week then placed in a cell culture chamber with one animal and 4 ml of seawater. At in...
J R Williams, S M Cragg, L M S Borges, B Shayler
Sustainability Through New Technologies for Enhanced Wood Durability. COST Action E37 – A New Action in the Forestry Domain
2004 - IRG/WP 04-40293
The main overall objective of the action is to concentrate on the contribution of wood durability on the sustainability through the development of systems for quality assurance and perfoamance of modified wood and wood products as alternatives to wood treated with traditional preservatives. By this means it seeks to improve and consequently increase the cost-effective use of sustainably produced E...
R-D Peek
Natural durability of wood in ground contact - A correlation between field and laboratory tests
1985 - IRG/WP 2182
A field test is being carried out to evaluate the natural durability of 20 hardwoods. The resistance to decay and termite attack was evaluated in accelerated laboratory tests. The results of the field test after 6 years and 8 months indicate that there is not necessarily agreement between results from laboratory and field tests. It is pointed out that apart from the artificiality of the laboratory...
M S Cavalcante, G A C Lopez, R G Montagna, M E S Fosco Mucci
Effects of artificial UV weathering and soft rot decay on heat treated wood
2005 - IRG/WP 05-40302
Oil and inert gas oven heat treated pine wood strips 100 µm thick were mildly heat treated (200°C, 30 mins linseed oil, 120 mins oven). Following treatment, specimens were exposed to UV weathering (300 hours) and decay by the soft rot fungus, Chaetomium globosum. The effects of each treatment were assessed by zero span tensile testing, microscopy and by FTIR.
Tensile testing of heat treated s...
M D C Hale, S C Ghosh, M J Spear
Natural resistance of different species of timber to marine borer attack in the Trondheimsfjord (Western Norway)
1978 - IRG/WP 435
Natural resistance of 34 timber species to marine wood-borers has been discussed, based on data collected from panels immersed in selected localities in the Trondheimsfjord during 1977-78. The wood-borers encountered on the panels were Psiloteredo megotara, Xylophaga dorsalis, Xylophaga praestans and Limnoria lignorum. The number of borers present and their growth were taken as the criterion for a...
L N Santhakumaran, J A Sneli
Durability of wood in the area of wood-inhabiting termites in Slovenia
1981 - IRG/WP 1139
This report describes a research dealing with resistance and durability of five different species of wood. The experiment was made in natural conditions in the Slovene area of wood-inhabiting termites. The results of our experimental field, which correspond to the results of the former laboratory experiments, show a very weak resistance of spruce-wood, fir-wood, and beech-wood. They also show thei...
L Kervina
Laboratory determination of the natural decay resistance of some lesser-utilized timbers from Tanzania against wood decay fungi
2004 - IRG/WP 04-10517
Four lesser known/utilized timber species (sap and heartwoods) from Tanzania, namely Albizia lebbeck, Zanthoxylum gilletii, Faurea saligna and Parinari curatellifolia were exposed to the brown rot fungi (Gloeophyllum trabeum and Coniophora puteana) and the white rot fungus (Coriolus versicolor) to determine their natural decay resistance according to the EN 113 standard procedure. The timbers were...
P R Gillah, R C Ishengoma, E Julias, S A Amartey, D H Kitojo
Natural durability of European wood species for exterior use above ground
2003 - IRG/WP 03-10499
The main interest in using more timber for exterior constructions is to protect the environment, where wood is considered an environmentally friendly material. However, chemicals for wood protection are getting more and more restricted, consequently, the focus on the natural durability of wood is increased. Good, well-documented data on the durability of wood species in ground contact exist, which...
B Lindegaard, N Morsing
The chemical analysis and biological evaluation of wood extractives as potential timber preservatives
1995 - IRG/WP 95-30090
Work involved the biological performance of water and organic solvent soluble extractives of four naturally durable wood species, namely; Matumi, Tamboti, Sneezewood and the Turpentine tree. These timber species are known to be naturally durable against termites and fungi (±25 to 35 years). The extractives were evaluated against termites and fungi using impregnated pine pencil stakes in field tes...
P Turner, D Conradie
Moisture condition in treated wood exposed outdoors. A progress report after 5 years
1992 - IRG/WP 92-3720
Wood treated with water-borne preservatives, mainly CCA (copper, chromium and arsenic) and CCB (copper, chromium and boron) is often said to absorb more water than untreated wood. In laboratory tests this statement has not been confirmed (Johansson 1977). In 1986 a project was started to compare water absorption during outdoor exposure between wood stakes of pine, Pinus sylvestris L, and spruce, P...
M-L Edlund
Photo-discoloration and Degradation of Wood and its Stabilisation by Modification with Benzoyl Chloride
2004 - IRG/WP 04-40274
Photo degradation of Pinus roxburghii (chir pine) and Hevea brasiliensis (rubber wood) was studied under artificial accelerated weathering conditions in a Xenon test chamber. The irradiated samples were analyzed for color changes and chemical changes. Analysis of colour changes in wood surfaces by UV-Vis. irradiation was carried out using a colour measuring (CIELAB) system and chemical changes ...
K K Pandey
Natural durability of Iranian saxual wood (Haloxylon persicum) against the fungal decay
1991 - IRG/WP 1515
Haloxylon persicum is vidly planted in the deserfic region of Iran. At the present time, in the age of 30, these small trees are ready for cutting for the different uses, specially for rural buildings. But there's any knowledge about its durability. In this study the laboratory tests were carried out in accordance to European Standard. 5 fungi were used as: Trametes versicolor, Coniophora...
D Parsapajouh, F H Schweingruber, K Richter
Decrease of the antidecay resistance of beech wood treated with organotin fungicides after its natural ageing
1998 - IRG/WP 98-30185
The antidecay resistance of beech-wood samples (120 x 8.5 x 8.5 (MM)) treated with tributyltin fungicides gradually decreased due to prolongation of their natural ageing:
tributyltin fungicides (TBTO, TBTS, TBTCA, TBT-DEDTK were applied by pressure impregnation technique in ethanole solutions (c = 0. 1%, 0.33% or 1%);
treated beech-wood samples were naturally aged without their contact with grou...
L Reinprecht
Study of the degradation of retified wood through ultrasonic and gravimetric techniques
1994 - IRG/WP 94-40030
One of the non-polluting processes that increase the natural durability of wood is a thermal treatment in an atmosphere poor in oxygen, producing what is normally denominated "retified wood". In this study the validity of a non-destructive technique (ultrasound) in order to determine the biodegradation suffered by wood across time has been studied. For this reason, the behavior of a wood species (...
D T De Troya, A M Navarrete
Effect of vegetable compost on leaching of CCA components from treated wood - An Update
1995 - IRG/WP 95-50048
In an earlier study, the effect of compost on CCA-C leaching was compared with leaching losses under different exposure conditions. Small treated cubes (25 mm³) were destructively sampled over a 12 month period and the residual CCA determined for exposure to compost in a compost bin, exposed to natural rain and buried in soil. This study provides a comparison after 3 years of samples exposed to c...
P A Cooper, Y T Ung
An in-ground natural durability field test of Australian timbers and exotic reference species. Part 5: Extensive data from a site where both decay and termites are active. Results from a full-replicated set of heartwood specimens from each of ten myrtaceous hardwoods after 18, 19 and 20 years' exposure - A discussion paper
1988 - IRG/WP 2324
Extensive data are presented on the decay situation, the termite situation and the decay-termite associations; all gathered from a fully-replicated set of heartwood specimens of 10 hardwood timbers after 18, 19 and 20 years' exposure in the ground at a single test site, i.e. a semi-arid steppe site. Sixteen tables are presented in addition to the one table providing the rating data; the l...
J D Thornton, G C Johnson, J W Creffield
UV-microspectrophotometry of lignin and accessory compounds in wood cell walls of conifers
1999 - IRG/WP 99-20171
The distribution of lignin in the cell wall of conifer tracheids was determined by UV-VIS microspectro-photometer. Wood sections of one micron thickness were measured between the wavelength 240 and 700 nm. Spectral analyses revealed that the conifer lignin associated with the tracheid secondary wall and middle lamella is composed of guiacylpropane units which exhibit a characteristic UV absorption...
G Kleist, G Koch, J Bauch
Resolution from IRG Working Group II Sub-group 4 'Stain in timber in service'
1984 - IRG/WP 2230
Sub-group 4 of IRG Working Group II has completed a series of studies of artificial weathering as an alternative to natural weathering in relation to testing the efficacy of chemicals in preventing blue stain in service. The Sub-group reports that within the limits of the equipments studied and described in its report Document No: IRG/WP/2215 the extent of blue stain varied little as a direct cons...
D J Dickinson