Your search resulted in 427 documents. Displaying 25 entries per page.
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
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
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
Xenon simulation of natural weathering of external joinery preserving - Finishing systems
1992 - IRG/WP 92-2412
Semitransparent wood stains ('lazures') for external joinery have developed by means of product combination towards complete wood finishing systems that are easy to applicate, have a good weathering resistance and low maintenance cost. The search for enhanced formulations and the possibilities to standardize these products or treatment systems are always facing long periods of we...
J Van Acker, M Stevens, M Nys
Durability of plywood made from soft- and hardwoods assessed according to ENV 12038 after artificial and natural ageing
2000 - IRG/WP 00-20191
Plywood was prepared from Norway Spruce and pure heartwood of Douglas Fir, Scots Pine, European Oak, False Acacia and Macoré using a phenol-formaldehyde glue. The panels of 38 mm in thickness were pre-conditioned according to the following procedures: a) 12 weeks storage at 20°C/65% rh, b) 2 weeks artificial weathering (with rain and UV-radiation at changing temperatures), and c) a natural weath...
H Leithoff, R-D Peek
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
Bioassays of extracts from scaly ash (Ganophyllum falcatum B1) against the subterranean termite Coptotermes acinaciformis (Froggatt)
1983 - IRG/WP 1206
Scaly ash, Ganophyllum falcatum B1. wood shavings were extracted by methanol, and fractionated with ethyl acetate, diethyl ether and water, and the anti-termitic properties of these materials bioassayed against the subterranean termite Coptotermes acinaciformis (Froggatt). Laboratory techniques were developed to overcome the problem of limited extractive materials. The results of the various bioas...
J R J French, J P Robinson, J W Creffield
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
Natural weathering of wood in a sunny climate effects on surface chemistry and paint adhesion
1997 - IRG/WP 97-20109
Radiata pine veneers and blocks were exposed to natural weathering under Australian summer conditions over a period of 30 days. Infrared spectroscopy revealed that there was perceptible surface delignification after 4 hours exposure, substantial surface delignification after 3 days exposure and almost complete surface delignification after 6 days. Viscometry determinations on holocellulose samples...
P D Evans, P D Thay, K J Schmalzl
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
Natural exposure weathering tests: Their role in the assessment of wood preservative efficacy
1993 - IRG/WP 93-20006
Previous work has demonstrated the potential and usefulness of natural ageing procedures in e evaluation of wood preservative efficacy. This results from the combination of physico-chemical influences and microbiological interactions with both substrate and wood preservative. In this paper, results are presented for a range of biocide types. Discussions are centred on the value of natural exposure...
G R Williams, J Brown
Wood extractives as carbon sources for staining fungi in the sapwood of lodgepole pine and trembling aspen
1995 - IRG/WP 95-10098
Wood discoloration by sapstaining fungi reduces lumber value. In Canada, the most commonly recorded sapstaining fungi belong to the genera Ophiostoma. This work evaluated the effect that Ophiostoma piceae, Ophiostoma ainoae, and Ophiostoma piliferum used the lipids present in the sapwood of lodgepole pine (Pinus contorta Dougl.) and trembling aspen (Populus tremuloides Michx.). Wood lipids, common...
Yong Gao, C Breuil
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
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
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
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