Your search resulted in 724 documents. Displaying 25 entries per page.
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
The colonization of selected naturally durable timbers by marine fungi and borers
1977 - IRG/WP 439
In recent years, concrete and metal have been widely substituted for wood in contact with sea water, but wood products have not lost their usefulness under such conditions. In many cases, wood if sound and durable, may prove to be the most practical and economical of materials used in sea water exposure. Timber when immersed in the sea may be attacked by micro-organisms (bacteria and fungi) and ma...
S E J Furtado, E B G Jones
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 2: Laboratory fungal bioassays
2000 - IRG/WP 00-20204
Extracts from sawmill residues of the naturally durable white cypress, Callitris glaucophylla were tested for fungicidal activity in a series of laboratory bioassays. The effects of different extraction solvents, techniques and sources of material on the biocidal efficacy of the resultant extracts were evaluated. Soil jar decay tests were used initially however, contractual time constraints necess...
M A Powell, L M Stephens, L Francis, M J Kennedy
The natural durability assessment of secondary hardwood species - laboratory tests
1998 - IRG/WP 98-10295
Laboratory tests have been undertaken to assess the natural durability of 16 species of lesser known hardwoods, or hardwoods from non-traditional sources, including teak from three different plantations. Resistance to decay by both basidiomycetes and soil-inhabiting micro-fungi has been established.
´The data indicated that published information on the durability of these timbers should be treat...
J K Carey, S J Hendry
Some experiences with attack of microorganisms on wooden constructions supporting foundations of houses and bridges
1997 - IRG/WP 97-10232
Reconstructions of bridges and public buildings or damage of houses during the construction of subway lines in Berlin have led to a number of inspections of wooden foundations, mostly pine or spruce piles, representing service lives of between ca. 70 and 140 years. In all cases bacterial attack was found both in wood submerged in ground water and in surface water. The extent of deterioration diffe...
M Grinda
Termite and decay resistance of particleboard composed of white cypress pine and radiata pine
1997 - IRG/WP 97-10200
Phenol-formaldehyde bonded particleboard was manufactured from blends of non-durable radiate pine (P. radiate) and heartwood of the naturally durable species, white cypress pine (C. glaucophylla). Board specimens were subjected to bioassays using two termite species, M. darwiniensis and C. acinaciformis, and the basidiomycete fungi, C. puteana and P. ostreatus, and the durability of specimens was ...
P D Evans, J W Creffield, J S G Conroy, S C Barry
Natural decay resistance of some lesser-used tropical hardwoods from Ghana
2002 - IRG/WP 02-10438
Ghana is a tropical African country that is rich in diverse timber species. In order to reduce over-exploitation of the popular timber species and increase the resource base for the wood industry, lesser-used or lesser-known timber species are being promoted locally and for export. To do this successfully, it is essential to determine the physical, mechanical and biological properties of these tim...
S A Amartey, F R Hanson
The use of modulus of rupture and modulus of elasticity in natural durability testing
1997 - IRG/WP 97-20117
Losses in weight, losses in bending strength and changes in elastic behaviour were assessed in a fungus cellar test with beech wood stakes (Fagus sylvatica). Results were gained after 8, 12, 16 and 20 weeks resp . The outcomes show, that the non-durable species beech is very rapidly attacked by fungi and loses up to 60% of its initial bending strength even within the first 8 weeks. Earlier researc...
L Machek, H Militz, W Gard
Durability of Wood Plastic Composites Relative to Natural Weathering and Preservative Treatment With Zinc Borate
2005 - IRG/WP 05-40316
Wood-Plastic Composites (WPCs) used for decking have experienced dramatic increases in North America, averaging 25% growth per annum since 1998. A key factor contributing to this growth has been the successfully communicated message that they are "virtually maintenance free". The common perception being that the wood fiber is completely encapsulated by the thermoplastic resin, minimizing the pot...
M E Mankowski, F M Ascherl, M J Manning
Evaluating the natural durability of native and tropical wood species against Reticulitermes flavip
2004 - IRG/WP 04-10539
Environmental pressures to eliminate arsenate from wood preservatives has resulted in voluntary removal of CCA for residential applications in the United States. A new generation of copper organic preservatives has been formulated to replace CCA for decking and in-ground applications but there is no guarantee that these preservatives represent a permanent solution to all related problems. There...
R A Arango, F Green III, K Hintz, R B Miller
The influence of the natural extractives of opepe (Nauclea diderrichii) and African padauk (Pterocarpus soyauxii) timbers on their durability
1996 - IRG/WP 96-30098
Many timbers contain chemical extractives that undoubtedly play a key role in the timber's natural durability. Opepe (Nauclea diderrichii) and padauk (Pterocarpus sp.) are both very durable timbers (class 1), yet they are described as being moderately permeable. This suggests the presence of biocidal chemicals within these timbers, rather than simple blocking agents. Initial trials on the...
E D Suttie, R J Orsler
Fungal-termite associations in the natural resistance of selected eucalypt timbers
1978 - IRG/WP 173
Butt billets of Eucalyptus regnans F. Muell., Eucalyptus grandis W. Hill ex Maiden, and Eucalyptus camaldulensis Dehnh., showing no visible signs of decay, were examined for the presence of fungi in outer, middle and inner heartwood. Fungi obtained in pure culture were characterized. Eucalyptus regnans yielded Cytospora eucalypticola van der Westhuizen, Trichoderma harzianum Rifai and Penicillium ...
D B A Ruyooka
Natural Durability of Tropical Species – Variations and Prospects
2005 - IRG/WP 05-10568
The tropical timber resources of the world play an unequivocal role in economic development of both the tropical timber producing and importing regions. This paper describes natural durability as an important and preferred wood quality of tropical species of the world with emphasis on Malaysian hardwoods, the link between various aspects of tropical hardwood durability, hardwood utilization and bi...
A H H Wong, Yoon Soo Kim, A P Singh, Wang Choon Ling
Marine exposure assessment of the natural resistance of a number of lesser known species of tropical hardwoods to teredinid and limnoriid borers
2004 - IRG/WP 04-10520
Naturally durable species of timber are used as an alternative to preservative treated timber for marine structures, but many species have not been evaluated for their potential for use in this environment. EN 275 specifies a 5-year test period - too long a period for screening tests to be economically viable. In this study, candidate timber species were selected for testing in the sea on the basi...
J R Williams, S M Cragg, L M S Borges, J D Icely
Soft rot decay of Belian (Eusideroxylon zwageri) wood
1995 - IRG/WP 95-10119
The heartwood of Belian (Eusideroxylon zwageri), an East Malaysian timber species, is naturally durable due to its certain unique anatomical features and high content of extractives. The timber can tolerate years of exposure to hazardous conditions in ground contact and other situations without any significant loss in its strength. A few Belian transmission poles sampled from one locality in Saraw...
A H H Wong, A P Singh
Termite resistance of Malaysian and exotic woods with plantation potential: Laboratory evaluation
1998 - IRG/WP 98-10280
The resistance of selected Malaysian woods to attack by the representative aggressive subterranean termite Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) was evaluated in four-week, no-choice laboratory tests. This is part of an ongoing effort between the Forest Research Institute Malaysia and the University of Hawaii to document the termite resistance of Malaysian timber species of po...
J K Grace, A A H Wong, C H M Tome
MDF manufactured from blends of cypress pine and radiata pine shows enhanced resistance to subterranean termite attack
2001 - IRG/WP 01-40214
Medium density fibreboards consisting of blends of the naturally durable wood species white cypress pine (Callitris glaucophylla) and non-durable wood species were manufactured in a commercial plant and subjected to a bioassay using the subterranean termite species, Coptotermes lacteus. A board composed of 30% cypress pine, 30% slash pine (Pinus elliottii) and 40% of the naturally durable hardwood...
P D Evans, S Dimitriades, C Donnelly, R B Cunningham
The natural durability of wood in different use classes
2003 - IRG/WP 03-10457
The natural durability of important European wood species has been tested on 3970 specimen in field trials. The wood was exposed at five test fields in Germany with different climates at each site in European hazard class 4 and 3 (with and without soil contact). Within EHC 3 it was distinguished between tree different expositions (end grain sheltered, unsheltered and with water trap).
The test is...
U Augusta, A O Rapp
Assessment of wood decay in small-scale unsterile soil-bed tests
1997 - IRG/WP 97-20111
This study is concerned with the investigation of wood decay in small-scale unsterile soil-bed tests. Tests were performed with untreated heartwood samples from five hardwood species of different natural durability classes ranging from highly perishable to very resistant. Our results confirmed the critical role of soil moisture content on wood decay. The highest decay rates were observed at moistu...
L Machek, A M Derksen, R Sierra-Alvarez
The natural durability story
1997 - IRG/WP 97-20119
Wood species with superior natural durability were in use since the beginning of timber utilisation. Their importance decreased with increasing industrial timber impregnation. In recent time, however, they gained worldwide new interest due to environmental problems involved with treated timber. In Europe a special Standard (EN 350) has been published and a multinational research project on testing...
H Willeitner, R-D Peek
Durability of five wood species against Coriolus versicolor
1992 - IRG/WP 92-1578
The durability of following five wood species Zelkova carpinifolia, Ulmus glabra, Carpinus betulus, Acer trauvetteri and Pterocarya fraxinifolia were studied against Coriolus versicolor under laboratory conditions according to DIN 52176 standards. Zelkova caprinifolia shows a reduction in weight of 2.19%, Ulmus glabra 41.69%, Carpinus betulus 45.64%, Acer trauvetteri 53.05%, and Pterocarya fraxini...
S M Kazemi
Natural resistance of Bamboo (Bambusa sp.) to marine wood-borers in Goa waters (India)
1993 - IRG/WP 93-10032
The paper deals with the natural durability of Bambusa sp. against the attack of marine wood-borers in Goa waters. Test specimens of this species were completely destroyed within a short period of nine months due to severe attack of borers indicating its very low natural resistance. Wood-borers involved were Martesia striata (Linnaeus), Nausitora hedleyi Schepman and Lyrodus pedicellatus (Quatrefa...
L N Santhakumaran, S G Sawant
Comparing the resistance of a number of lesser known species of tropical hardwoods to the marine borer Limnoria using a short term laboratory assay
2003 - IRG/WP 03-10500
Naturally durable species of timber are used as an alternative to preservative treated timber for marine structures, but many species have not been evaluated for their potential for use in this environment. EN 275 specifies a 5-year test period - too long a period for screening tests to be economically viable. In this study, durability was assessed by measuring the production of faecal pellets by ...
L M S Borges, S M Cragg, J R Williams
Natural durability of 4 different Larix species tested in soil contact
2002 - IRG/WP 02-10434
Importers of Siberian Larch claimed to have a material which can replace pressure treated wood in soil contact. This gave reason to investigate the durability of 4 different Larix species (L. decidua, L. sibirica, L. decidua x sibirica, L. gmelini var ologenis) coming from 7 different origins in comparison with sapwood of Pinus sylvestris untreated as well as pressure impregnated with retentions o...
A O Rapp, H Viitanen, T Nilsson