Your search resulted in 85 documents. Displaying 25 entries per page.
Fire resistance of preservative treated fence posts
1994 - IRG/WP 94-30033
Pine fence posts were pressure treated separately with CCA-C, CCA-wax, CCA-oil and creosote. Treated posts and untreated controls were planted in the ground in a randomised block design, weathered for six months and then subjected to a controlled burning test using two fuel loads. Creosote treatment increased the time that posts were alight whereas CCA treatment had no such effect. However, CCA tr...
P D Evans, P J Beutel, C F Donnelly, R B Cunningham
Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observ...
P D Evans, S Thein
The leaching of copper, chrome and arsenate from CCA-impregnated poles stored for ten years in running water
1978 - IRG/WP 3122
There is no evidence to indicate that the chromium and copper components are leached from the outermost 5 mm of sapwood in poles impregnated with Boliden K33 and Tanalith C and stored in running water for ten years. The arsenic component, however, seems to be leached out during the first few months to an extent of about 20% of the initial amount. The leaching time is dependent on the preservative ...
F G Evans
The variation in electrical resistance in the CCA-treated wood during the fixation
1989 - IRG/WP 3554
The curve commonly used in Scandinavia for describing the fixation period at different temperatures for CCA-impregnated wood is based on investigation by Dahlgren on the pH-variations in a mixture of sawdust and preservative solution. As far as we know there is no such investigation on solid wood. We have therefore measured the electrical resistance in CCA-treated solid wood to see if this will di...
F G Evans, B Nossen
Field Test Results after Nine Years for CCA and ACQ Preservative-treated Wood Fixed in Different Climates
2003 - IRG/WP 03-30303
During assessment of the ground contact stakes in the Norwegian test field, we have frequently found that the first visual rot attack is in the zone of the stakes, where the stakes have been in contact with each other during the fixation. These parts are usually light green, caused by the lack of light during fixation, compared to the rest of the stake surface, which has a darker colour. To inves...
F G Evans
Restriction for use and waste management for pressure treated wood - The current situation in Norway
2001 - IRG/WP 01-50175
The Norwegian Environmental Authorities have this winter sent out a draft on restrictions in production and use of heavy metals in preservative treated timber. If it is passed, it will lead to drastic changes in the use of preservatives in Norway from this autumn. The environmental authorities and the preservative industry are both at present discussing waste management for CCA and creosote treate...
F G Evans
Patterns of long-term performance - How well are they predicted from accelerated tests and should evaluations consider parameters other than averages?
1998 - IRG/WP 98-20130
This paper is a discussion of whether different service-life distribution patterns of products treated with unlike preservatives can be predicted, modeled, characterized, or even anticipated from accelerated laboratory tests. Graphic displays of data from Forest Products Laboratory field plots with preservative-treated and fire-retardant-treated stakes demonstrate the importance of local environme...
R C De Groot, J W Evans
The use of ESR spectroscopy to assess the photostabilising effects of wood preservatives
2000 - IRG/WP 00-20186
The degradation of wood surfaces exposed to UV light which leads to poor performance of clear coatings is understood to be due to delignification via a mechanism involving free radicals. Certain wood preservatives most notably CCA are able to photostabilise wood and therefore they may reduce the concentration of free radicals formed when treated wood is exposed to ultraviolet light. As a first ste...
S Schmid, R D Webster, P D Evans
Retention and distribution of copper/chrome/arsenic (CCA) in pressurised sap-displaced UK grown spruce and pine
1986 - IRG/WP 3366
Increment cores were taken from UK grown Scots pine (Pinus sylvestris L.), Corsican pine (Pinus nigra var. maritima Ait), Sitka Spruce (Picea sitchensis (Bong) Carr), and Norway spruce (Picea abies (L) Karst) distribution poles treated by pressurised sap-displacement using a 1.8% copper, chrome, arsenic (CCA) solution. Each increment core was sectioned radially and the copper, chrome, and arsenic ...
P D Evans, G M Smith, B King
Restrictions or environmental taxes as regulatory means - How will they influence the use of pressure treated wood?
1998 - IRG/WP 98-50101-28
In all the Nordic countries except Norway, we have environmental restrictions on the use of pressure treated wood. In Norway we expect environmental taxes on a large number of various products in 1998/99 - probably also pressure treated wood with one or more of the heavy metals copper, chromium and arsenic. The paper will discuss how this can influence the use of pressure treated wood and cause a...
F G Evans
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
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
Experiences with penetration of copper-based wood preservatives
2001 - IRG/WP 01-20233
In the Nordic countries there is a long tradition of result type based specifications for preservative-treated wood. A common Nordic standard for treated pine (Pinus sylvestris) wood was published in 1976. After a revision in 1989 this standard, then named INSTA 140, defined four classes of treated wood: M, A, AB and B. Treaters producing according to this standard had to be affiliated to a qualit...
J Jermer, F G Evans, I Johansson
Improving the weather resistance of glue-laminated jarrah and karri
1994 - IRG/WP 94-40017
Surface modification and dimensional stabilisation significantly increased the dry and wet shear strength of karri and jarrah lap-shear specimens (laminates) bonded with resorcinol formaldehyde. The combination of surface modification (sanding/sodium hydroxide treatment), and furfurylation produced the highest dry and wet shear strengths. Acetylated laminates had the lowest dry bond strength, but ...
J Balfas, P D Evans
Size of food resource determines brood placement in Reticulitermes flavipes (Isoptera: Rhinotermitidae)
2000 - IRG/WP 00-10351
Most species of subterranean termite house and care for larvae in specialised chambers or complex nurseries. In addition to these chambers, the genus Reticulitermes also keeps larvae at sites where foragers are feeding, a trait more commonly found in damp wood and dry wood termites. This phenomenon of holding larvae at foraging sites is quite well known among researchers who work with Reticuliterm...
M Lenz, B M Kard, J K Mauldin, T A Evans, J L Etheridge, H M Abbey
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
The degradation of wood surfaces by water
1984 - IRG/WP 3289
Thin radial/longitudinal sections (~100 µ) of Scots Pine (Pinus sylvestris) and lime (Tilia vulgaris), were exposed to deionised water over the temperature range 25-65°C. Losses in wet tensile strength and toughness occurred rapidly at temperatures from about 50°C upwards. After about 2 months' exposure pine lost some 10-30% of its tensile strength and 20-60% of its toughness. For lime...
W B Banks, P D Evans
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 suitability of high pressure sap-displacement for the retention of UK grown spruce and pine
1990 - IRG/WP 3595
The concentration and radial distribution of copper, chrome, arsenic (CCA), and the moisture content and depth of radial checking in UK grown, field exposed spruce and pine poles treated by high pressure sap-displacement are examined. The concentration of CCA elements in samples obtained from increment cores is similar in Norway spruce, Scots pine and Corsican pine but is significantly lower in Si...
P D Evans, S D Hainey, A Bruce, G M Smith, B King
A technique for the rapid assessment of wood surface degradation during weathering
1987 - IRG/WP 2281
Radiate pine (Pinus radiata D. Don) sapwood samples taken from four trees were converted into thin strips 100 x 10 x 0.085 (85 µm) mm³, (longitudinal x radial x tangential) in size and exposed in preweighed hatches to the weather inclined at 45° facing equatorially for 10, 20, 40, 60, 80 and 100 days. Significant (P < 0.001) weight losses occurred with time over the exposure period. Differen...
P D Evans, D Abbott, S Thein
Leaching from CCA-impregnated wood to food, drinking-water and silage
1987 - IRG/WP 3433
During the last years The Norwegian Institute of Wood Technology (NIWT) has analysed different foodstuff for contamination by copper, chrome and arsenic from CCA-impregnated wood. There has been some interest for using CCA-impregnated wood in contact with food and drinking-water. Before giving their permission the Norwegian Health Authorities want results from experiments. NIWT therefore started t...
F G Evans
Durability of surface coating systems. Mycologg - an accelerated mycological test.
2004 - IRG/WP 04-20301
Field testing and natural aging/degradation of test sample, e.g. coated wooden surfaces is a slow process. Accelerated tests focus on mechanical properties, water uptake or sometimes stain fungi. Artificially weathered coated panels are not easily compared with naturally aged panels, and show the importance of involving the biological component among the degrading facors. It is a need for acce...
L Ross Gobakken, J Mattsson, B Jacobsen, F G Evans
Rapid loss of lignin at wood surfaces during natural weathering
1992 - IRG/WP 92-2390
Thin veneers of radiata pine (Pinus radiata D. Don) were exposed to natural weathering over a period of 30 days. Incident UV radiation was monitored at the test site. FTIR internal reflectance spectroscopy was used to study the chemical changes taking place at the veneer surface during weathering. Spectra obtained show that after only 3 days exposure there was substantial delignification at veneer...
P D Evans, K J Schmalzl, A J Michell
The relationship between the electrical resistance and fixation of water-borne CCA salts and pressure-treated wood
1991 - IRG/WP 3657
Two investigations at 22°C and 30°C have been carried out. The electrical resistance in the treated wood and chemical analyses of the remaining amount of unfixed copper, chromium and arsenic were investigated. Samples impregnated with water were used as references. To hold the samples moist during the investigation, each sample was wrapped in a polyethylene plastic foil immediately after impregn...
F G Evans, B Nossen
Field and greenhouse testing of window joinery of pine and spruce treated with LOSP
1991 - IRG/WP 3658
Norwegian window frame components of full size were double vacuum-treated with TBTN and TBTO, and connected as 'L-joints' and subsequently coated with stains. The corner sections were exposed (out of ground contact) both in field (temperated coastal climate, Taastrup, Denmark) and in a greenhouse (Uppsala, Sweden). The window frame L-joints of spruce (Picea abies Karst.) - treate...
F G Evans, B Henningsson, E Borsholt