Your search resulted in 1075 documents. Displaying 25 entries per page.
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 tests, a possible cause of the discrepancies can be the different performance of the same wood species in different test sites.
M S Cavalcante, G A C Lopez, R G Montagna, M E S Fosco Mucci
Ground contact performance of wood treated by the MSU process
1990 - IRG/WP 3609
Environmental concerns have prompted a renewed interest in accelerated fixation schemes for CCA-treated wood. Results from stake tests of southern pine (Pinus sp.) treated using a conventional Bethell cycle are compared with matched stakes treated using the MSU Process. The effects of adding boric acid to the preservative formulation are also discussed. Differences among test plots are discussed.
H M Barnes, T L Amburgey, R W Landers
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 subterranean termite Coptotermes curvignathus was chosen for study. The accelarated test protocol consisted of burying small (2 x 2 x 2 cm3) wood blocks of the following timber species at 15-20 cm below-ground with the immediate environment manipulated by addition of residues from oil palm fibres and venners of decay susceptible woods and concealed with forest top soil: Casuarina equisetifolia, Azadirachta excelsa, Tectona grandis (both Malaysian-grown and Burmese material), Hevea brasiliensis, Acacia mangium, Albizia falcataria, Araucaria cunninghamii, P. sylvestris, Koompassia malaccensis and K. excelsa. After 28 days, it was found that the results of the subterranean termite resistance test are consistent with the known/expected termite resistance of these woods when compared with previous natural durability stake test records of FRIM.
A H H Wong, J K Grace, L H Kirton
Accelerated testing for out of ground contact using natural biological preconditioning
1996 - IRG/WP 96-20088
Small blocks made of Scots pine sapwood were treated, buried in vermiculite and exposed to natural microbial colonisation during outdoor exposure prior to laboratory decay testing. Periodic microbial isolations, moisture content, permeability and weight loss tests were also conducted. Bacteria and moulds colonised the vermiculite and miniblocks well. Aureobasidium pullulans was common on TnBTO treatments. Basidiomycetes were isolated from the control miniblocks at 3 months. Controls showed slightly increased permeability compared with treated samples after 1 month. At 3 months, controls, all TnBTO treated blocks and the lower retentions of DDAC showed permeability increases. Weight loss in the field was low up to three months, even in the controls (3.5%). Agar block trials with no natural pre conditioning showed all preservative treatments were effective, but, after only 1 month's field exposure the lowest retentions no longer provided adequate protection. Further studies are in progress.
S Molnar, D J Dickinson, R J Murphy
Some Experiences with Stake Tests at BAM Test Fields and in the BAM Fungus Cellar
Part 1: Comparison of Results of Visual Assessments and Determinations of Static Moduli of Elasticity (MOE)
2005 - IRG/WP 05-20319
With examples of routine in-ground stake tests differences are shown in the performance of wood preservatives at the BAM test fields Lehre and Horstwalde and in the BAM fungus cellar. Signs of attack of micro-organisms were assessed visually according to EN 252. Periodical determinations of static moduli of elasticity (MOE) revealed the influence of the attack on the elastic properties of the wood specimens. The course of visible signs of attack and the residual MOE corresponded sufficiently in the fungus cellar. At comparable decrease rates of the MOE the visible signs of fungal attack developed slower at the test fields than in the fungus cellar. The stake dimensions distinctly influenced the accelerating effect of the fungus cellar.
M Grinda, S Göller
Wood preservatives: Field tests out of ground contact. Brief survey of principles and methodology
1976 - IRG/WP 269
This paper contains the following spots: 1.: The general need for field tests. 2.: Interests and limits of field tests in ground contact. 3.: Various methods in use for out-of-ground contact field tests. 4.: Fungal cellar tests are they an alternative to above-ground decay exposure tests? 5.: Conclusions.
Japan's comments on ISO/DIS 12583-1/2
1996 - IRG/WP 96-20100
The paper describes an accelerated field test for the evaluation of timber preservative formulations against subterranean termites. The method has been adopted by the South African wood preservation industry as a screening method for the approval of wood preservatives for use under SA conditions. The method which is based upon the fungal cellar test offers a rapid means of evaluating the comparative performance of new wood preservative formulations in an environment that accurately reflects field conditions.
P Turner, D Conradie
Field tests out of ground contact in France: Definition of the test procedure and preliminary results after 18 months
1981 - IRG/WP 2161
In-ground performance of two formulations of chlorothalonil after five years of exposure at three test sites in Australia
1996 - IRG/WP 96-30101
Sapwood specimens of Pinus radiata D. Don and Eucalyptus regnans F. Muell. were each treated to three retentions of each of two preservative formulations (chlorothalonil in oil; chlorothalonil plus chlorpyrifos in oil) and installed in-ground at three field test sites in Australia. Specimens were treated with each formulation to achieve 3.2, 6.4 and 12.8 kg/m³ of chlorothalonil a.i. and 3.2 + 0.2, 6.4 + 0.4 and 12.8 + 0.8 kg/m³ of chlorothalonil plus chlorpyrifos a.i. For comparison, specimens of each timber species, treated to a commercial in-ground retention of a copper-chromium-arsenic (CCA) formulation, were also installed. Treated specimens (including controls) have been rated for their condition annually for attack by subterranean termites and fungal decay using a scale ranging from 4 (sound) down to 0 (failed). After five years of exposure, mean termite and decay scores for replicate test specimens at each site reveal that the performance of all three retentions of each formulation, particularly the two highest retentions, is comparable to CCA.
J W Creffield, T L Woods, N Chew
Short-term field test method with accelerated infection of Basidiomycetes in wood
1981 - IRG/WP 2155
In the ŠIPAD - IRC Wood Protection Laboratory an attempt has been made to develop a simple short-term method for field testing out-of-ground contact wood using accelerated infections with Basidiomycetes. This method makes it possible to obtain a preliminary assessment of a preservative's quality and to estimate the possibility of achieving promising results in more expensive long-term tests. The idea was to use water traps (reservoirs) and 50 x 25 x 15 mm³ laboratory infected pine blocks as the substrate to improve the possibility of inoculation of L-joints.
Are fungal cellar tests really necessary?
1989 - IRG/WP 2333
During the past decade the range of methodology used to evaluate wood preservative potential has significantly expanded. At the forefront of these new tools available to the scientist·is the fungal cellar. This technique, as currently applied, involves the exposure of treated and untreated samples to conditions of moisture and temperature which ensure optimum fungal attack. By comparison data with that obtained on similar preservative systems in conventional stake tests, acceleration factors for predicting performance have been developed. This discussion paper examines the philosophy influencing the development of fungal cellar testing, and provides an alternative viewpoint.
J N R Ruddick
A new ground-contact wide-spectrum organic wood preservative: DNBP
1986 - IRG/WP 3358
A new organic wood preservative, which 25 years field tests have proved to be of efficiency and effectiveness comparable to CCA wood preservatives for ground-contact applications, is presented. Physical and chemical tests, supporting the long term field test results as well as indicating the characteristics of this preservative, are also presented.
W E Conradie, A Pizzi
Performance of surface-treated hardwoods and softwoods out of ground contact
1990 - IRG/WP 3592
A number of fungicides were tested as brush treatments for protection of southern pine, Douglas-fir, maple, and red oak against decay above ground. Cross-brace and L-joint test units were treated just before assembly and exposed from 3-10 years. Untreated Douglas-fir cross-brace units were not decayed at either the Mississippi or Madison, WI, site. Untreated red oak cross-brace units were not decayed at the Madison site. The two hardwood species were more difficult to protect from decay than the softwood species. Decay development in maple cross-brace units was considerably slowed by several of the treatments but none of the treatments provided complete protection from decay during the 9 or 10 years exposure in Mississippi. Most of the treatments did not reduce decay development in red oak cross-brace units. Many treatments protected pine cross-brace units. The L-joints were exposed for only 3-4 years, but appear more difficult to protect from decay than the cross-brace units.
T L Highley
Accelerated wood decay in a soil bed test under greenhouse conditions compared with a stake test under field condition
1991 - IRG/WP 2384
The rate of decay of oak, beech, Douglas fir, pine and spruce stakes in an outside test field were compared with the decay rate of the same species in a greenhouse soil-bed test. Strength loss after four and six months respectively was measured by determining the compression strength parallel to the grain. The results show that all species, strength loss in the greenhouse was 2 to 4 times higher than under field conditions. The rate of strength loss correlates with the rate of weight loss.
J E Polman, S G Michon, H Militz
Above ground testing of wood preservatives - some experiences from Sweden
1995 - IRG/WP 95-20079
Field stake tests for the evaluation of wood preservatives have been used for more than 50 years in Sweden. In the Nordic countries a system for approval of wood preservatives, which includes field test, has also been in operation for more than 25 years. This system has been described in an IRG Document by Henningson & Jermer (1988). The Nordic system is now in a process of harmonization with the European system based on CEN's hazard classes (Henningsson & Jermer, 1994). Strangely enough, field testing for approval purposes in Sweden and the Nordic countries has only been done with stakes in soil contact. In earlier days approval requirements for a preservative for above ground situations was determined on the basis of results obtained in stake tests. Subsequently the Nordic approval system accepted laboratory decay tests as an approval basis for above ground preservatives. The European Standard EN 113 or comparable methods were allowed. This means that wood preservatives for above ground use could be approved after only laboratory tests, which - as a matter of fact - was against the generally accepted testing philosophy in these countries. The absence of standardised methods for field testing of above ground preservatives, however, does not necessarily mean that such tests have not been performed in Sweden. In the following some examples of above ground testing will be given. Although these tests may not particularly have been designed for testing the efficacy of wood preservatives, they may be of interest in discussing methodology and they may be imptortant in special cases. The examples are: Test with plank pieces; Window-frame corners; Organotin degradation test; tests with piled samples; tests about the natural durability of wood panels.
B Henningsson, Ö Bergman
In ground contact field trial results of preservative treated incised and unincised spruce
1996 - IRG/WP 96-40076
Field trials of treated spruce stakes have been demonstrated that incising the stake before treatment improves the preservative uptake both for CCA and creosote. This results in a substantially extended service life for the incised stakes over the unincised stakes for preservative concentrations at commercial levels. After 24 years in ground contact the majority of incised spruce samples are sound and have provided data which indicates that the stakes treated with CCA or creosote to commercial standards could last for more than 41 years.
E D Suttie
Thirty-four year test of on-site preservative treatments to control decay in wood above ground
1993 - IRG/WP 93-30015
This research was initiated in 1958 to investigate efficacy of various preservatives and treating methods for new lumber going into exterior structures of buildings. Post-rail units (2x4 inches) constructed of Southern Pine sapwood, Douglas-fir heartwood, and mill run western hemlock were dip- or brush-treated before or after assembly. Units were trested with pentachlorophenol in various petroleum solvents or with copper napthenate in mineral spirits. Both painted and unpainted units were exposed on a test fence in Madison, WI. Most of the painted untreated pine units (controls) failed by 34 years. Surprisingly, painting completely protected the untreated Douglas-fir units from decay and afforded substantial protection to untreated hemlock. Significant decay in painted units was present only in lightly treated pine units (2-second dip after assembly or brush treated). Copper napthenate (1% copper) was markedly less effective than the penta treatments on unpainted pine and hemlock units. There was no evidence that type of oil carrier or incorporation of a water repellent improved effectiveness of treatment. Three or 15-minute dips in penta were equally effective. Penta-grease applied to unit ends only was effective.
T L Highley, T C Scheffer
Biological effectiveness of ground-contact wood preservatives as determined by field exposure stake tests
1984 - IRG/WP 3297
Field exposure tests conducted on stakes treated with different creosotes, mixtures of creosote and waxy oil as well as different CCA wood preservatives over a period of 25 years, gave the following results: The CCA preservatives provided excellent biological protection to treated stakes, especially against fungal attack. The CCA Type I, currently approved for use under South African conditions is not inferior to the CCA Type II during long-term ground-contact exposure if the active elemental contents and effective retentions are taken into consideration. The creosotes provided good protection against termite attack but showed fairly poor fungal resistance during long-term ground-contact exposure under wet conditions. The addition of waxy oil greatly improved the effectiveness of creosotes against fungal attack. The CCA preservatives proved to be a better overall ground-contact preservative compared with the creosotes.
W E Conradie, A Pizzi
Performance of treated spruce in Canadian field test sites
1989 - IRG/WP 3506
Spruce material under test in Canadian field test sites is performing better than anticipated. From the comparison of the performance of spruce treated with various preservatives, it appears that penetration may be far more important on durability performance than the preservative itself or the retention of preservatives in the wood. However, there is still insufficient data on the influence of penetration on the performance of treated spruce. As data for species other than white spruce and data for sawn material is also incomplete, spruce cannot be accepted by the Canadian standards at this time.
J P Hösli, E E Doyle
Long term performance of CCA preservatives in ground contact
2000 - IRG/WP 00-30223
Copper-chrome-arsenate (CCA) preservatives have been use extensively in New Zealand since the mid-1950s for a wide range of ground contact uses, radiata pine being the main species treated. They have been the subject of a comprehensive field testing programme in up to five sites in New Zealand, the earliest tests being established in 1955. Main factors affecting performance have been formulation type, test site and test specimen size. In nearly all tests where efficacy of CCA has been compared with other preservatives, CCA has been more effective in controlling decay, particularly on drier sites. In a warm and wet site (annual rainfall 2,000 mm) where soft rot and brown rot predominate, there has been very little difference in performance between CCA and other multi-salt formulations, but in a very wet site (annual rainfall >3,500 mm) CCB and CCP have out-performed CCA.
M E Hedley, D R Page, B E Patterson
In-ground evaluation of a copper azole wood preservative (Tanalithâ E) at a tropical Australian test site
1996 - IRG/WP 96-30100
A field trial to determine the in-ground termite and decay resistance of Pinus radiata D. Don impregnated with a copper azole formulation, TANALITHâ E, has been established at a tropical site in the Northern Territory of Australia. Four retentions of TANALITHâ E, containing 1.54, 2.08, 2.92 and 4.30 kg/m³ of Cu, are being evaluated. For comparison, Pinus radiata specimens treated to two retentions (0.56 and 1.18 kg/m³ of Cu) of the benchmark CCA preservative TANALITHâ C, have also been included in the test. Treated specimens (including controls) have been assessed for degrade by subterranean termites and fungal decay, after 4, 7, 16 and 27 months of exposure, using a scale ranging from 4 (sound) down to 0 (failed). Over the duration of the trial, specimens have been contacted by the economically important species of termites Mastotermes darwiniensis Froggatt, Coptotermes acinaciformis (Froggatt), Schedorhinotermes spp. and Heterotermes spp. After 27 months of exposure, the mean termite and decay scores for replicate test specimens indicate that the performance of TANALITH â E is comparable to CCA.
J W Creffield, J A Drysdale, N Chew
Fungus cellar testing as an evaluation method for performance of treated timber in ground contact
2001 - IRG/WP 01-20227
A fungus cellar method for the accelerated evaluation of performance of treated wood in ground contact is described. The test soil comprised of sandy loam, vermiculite and Japanese horticulture soil "Kanumatsuchi" in a ratio of 6:2:2 by volume. The soil was inoculated with the dominant test fungus isolated with selective medium from decayed wood samples. Pairs of treated and untreated wood specimens Japanese cedar in contact with each other were buried vertically for two thirds their length. Assessment of the specimens was carried out periodically using the FFPRI graveyard damage index six- grade scale. Important factors for accelerating decay were the moisture control of the mixed soil, temperature and relative humidity, and the maintenance of fungus activity. The fungus used for inoculation favored a soil water holding capacity (WHC) of 50-80%. Under these conditions the untreated control specimens had a damage index in six months equivalent to three years FFPRI graveyard test service life, the decay accelerating rate by the fungus cellar to the graveyard test was 6 times. Under higher soil moisture conditions (WHC>80%) in the fungus cellar, soft rot was dominant and the decay rate was slower. DDAC treated specimens (8.4kg/m3) had a damage index of 2.6 in three years and 3.0 in four years. DDAC treated specimens (8.2kg/m3) in the graveyard test have been shown to be durable for 12 years (damage index of 2.3 in ten years and 2.6 after 12 years). This fungus cellar method has been shown to accelerate decay in DDAC treated specimens 3 times or more in comparison to the FFPRI graveyard test. On the other hand specimens treated with Copper-azole (6.0kg/m3 as retention of actives) had a damage index of 0 after eight years. The average service life in the FFPRI graveyard test is not decided as the Copper-azole treated specimens are in sound condition so it is not yet possible to evaluate the accelerating rate for the Copper-azole by the fungus cellar method. The fungus cellar method will be an useful method for the accelerated evaluation of performance of treated wood in ground contact provided the test conditions can be controlled.
A termite field test with diffusion treated lumber
1991 - IRG/WP 3648
Douglas fir lumber, diffusion treated with concentrated sodium octaborate solutions, was tested against Coptotermes formosanus in an above ground field test wherein the samples were not exposed to a direct leaching hazard during the test period. After 2.5 years exposure, the untreated control samples were almost completely destroyed while poorly treated controls pressure treated with chromated copper arsenate had suffered only slight termite damage. Samples diffusion treated with 25% and 30% BAE solutions of sodium octaborate and held for an eight week diffusion period were subject to severe degradation from termite attack. The test methodology, treatment parameters, results and planned follow-up studies are described.
K J Archer, D A Fowlie, A F Preston, P J Walcheski
Attempt for developing a new method for above ground field testing of wood durability
2000 - IRG/WP 00-20199
Field testing remains the most appropriate way for evaluation of wood preservatives or natural durability of wood species. Above ground tests are designed to answer specific questions concerning the outdoor utilisation of wood. Such methods supply additional information and confirm or reject preliminary laboratory results. The European standard (ENV 12037, "lap-joint") for assessment of the durability of preservative treated wood in above ground testing has recently been proposed. It may also be used to assess the natural durability of wood. The objective of the present paper is to bear some discussion on alternative above ground test methods. The existing lap-joint field test corresponds to the real exploitation conditions of timber, but shows no decay after 2-3 years of exposure. This could be misleading when assessing the efficiency of preservatives. The method suggested acts more quickly compared to the lap-joint method with regard to mould, stain and, presumably, decay fungi. It is an accelerated above ground field test providing conditions favourable for fungal growth, but following close the fluctuations of climate. Results are shown where samples treated with preservatives for above ground use and untreated samples were exposed to the accelerated above ground test for several months. Fungal discoloration of the timber surface was classified by visual examination according to a seven-grade scale. The field test described here may be recommended for quickly testing of the natural durability of wood in above ground conditions as well as for approval of preservatives.
N Terziev, M-L Edlund
Above-ground field tests undertaken in New Zealand
1995 - IRG/WP 95-20063
In addition to "standard" L-joints, above-ground test material exposed at the NZ FRI test site includes treated and untreated decking units, Y-joints, fence battens and weatherboards either with or without additional protection from surface coatings. The latter tests bridge the gap between "model" test assemblies, such as L-joints, and services tests. Most tests are of preservative-treated radiata pine using proprietary formulations which were approved for above ground use at the time when each test was established. Other tests are natural durability tests to determine the suitability of those species, in terms of durability and mechanical properties, for above ground use without preservative treatment. The first tests were established in 1952 and results from those and subsequent tests have been used during periodic amendments to NZ wood preservation standards and specifications. The purpose of the different tests is described as well as pertinent results from them to illustrate their value.
M E Hedley, D R Page, J B Foster, B E Patterson