Your search resulted in 458 documents. Displaying 25 entries per page.
An investigation to assess the feasibility of developing an accelerated laboratory test to determine the abrasion resistance of lesser-used timber species for use in marine constructio
2005 - IRG/WP 05-20317
The paper describes the evaluation of a laboratory-accelerated test to compare the shingle abrasion resistance of current and potential timbers for use in marine construction. Useful results were achieved in 47.5 hours, but identified a number of issues to be resolved for the test to be refined and the subsequent results to be interpreted correctly.
G S Sawyer, J R Williams
Timber Preservation and Sustainable Construction in Australia
2005 - IRG/WP 05-50224-14
Sustainable development has been described as meeting the needs of the present without compromising the ability of future generations to meeting their own needs. (Bruntland 1987) To achieve the sustainable development goal therefore, the maximum performance has to be obtained from existing resources (timber) so that the remaining resource is protected from over-exploitation. Clearly, wood preservation has an important role to play in achieving the longest life from timber and timber products currently going in to service. Australia has a large number of naturally durable timbers and wood preservation systems have evolved to mimic and complement the natural durability of the heartwood of the material being treated. Whilst Australian wood preservative specifications have targeted the biological hazard and not the commodity, recent innovations with organic solvent preservatives have seen new products entering the market for very specific commodities. Consumer and specifier education remain a major issue for the wood preservation industry, even though specification and identification systems have been simplified as much as possible.
Valid scientific names of wood-decaying fungi in construction timber and their vernacular names in England, Germany, France, Sweden, Norway and Denmark
1992 - IRG/WP 92-1546
The valid scientific names of 100 species of wood decaying fungi in construction timber are listed, the citation of authors' names is standardized, and an index of the most commonly used synonyms is compiled. For each species vernacular names used in England, Germany, France, Sweden, Norway and Denmark are listed. The list of names is an attempt to update the current use of the most important species names used by specialists dealing with decay or discolouration of timber caused by fungi.
F Rune, A P Koch
Specifying preservative-treated resistant timber: Conforming to European Standards
2001 - IRG/WP 01-20235
The most common construction timbers used in the UK are of low natural durability and, generally, resistant to preservative treatment. These include species of spruce, hemlock and fir. However, their characteristically limited and non-uniform uptake of preservatives may still confer sufficient protection to give satisfactory durability performance in terms of biological resistance. This paper describes the results of a study investigating the protective efficacy of treatments defined according to the approach in European Standard EN 351-1 when penetration and retention values are used in timbers showing non- uniform treatment characteristics. The data show that variation between batches of samples is high for preservative uptake, retention and penetration. The biological data have given indications that this leads to differences in performance effectiveness. However, the bioassay method developed does not in its present form, sufficiently discriminate between treatment/species combinations.
E D Suttie, A F Bravery, T B Dearling
Molecular Methods: a Reliable Tool for the Identification of Wood Decay Fungi in Construction Timber
2008 - IRG/WP 08-20386
In the present study, we tested the practical value of several DNA-based methods to identify at the species level the most common wood-decaying fungi infecting buildings. We successfully extracted and amplified fungal DNA from pure cultures of twelve species of wood-inhabiting fungi, from oak and pine wood infected in laboratory with known strains, and from unknown field samples of wood collected from French buildings. Species identification was performed through PCR-RFLP analyses, species-specific priming PCR and sequencing of the rDNA ITS region. Our results mostly agreed with the data provided by previous authors, but also revealed some weaknesses of the methods used and provided additional information for future developments.
M Maître, M Kutnik, I Le Bayon, L Harvengt
Assessment of the marine borer resistance and abrasion resistance of lesser known hardwood timber species for use in marine construction
2010 - IRG/WP 10-10711
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 both in the laboratory and in the sea to establish their resistance to marine borer and abrasion. Comparative resistance was assessed by comparing the rate of deterioration observed in candidate species of lesser known hardwoods against that for greenheart and ekki which were used as benchmark species. A number of lesser-known timber species originating from South America and West Africa performed comparatively well in laboratory tests and over an eighteen month exposure period in the sea. Resistance to marine borer attack did not necessarily correlate with resistance to abrasion.
J R Williams, G S Sawyer, G Malyon, S M Cragg, J D Icely, J Simm, M Meaden
Riverbed Construction Technology using Thinned Timbers for Carbon Dioxide Sink in Korea
2010 - IRG/WP 10-50271
The Climatic Change Convention is a big burden in limiting the energy usage like the blood of economy. The certification standard about the carbon storage of timbers after harvesting them is expected to be an important role in setting the goal for future reduction of the green house gas(CO2). The extension of a timber's life span through its preservation is one of technologies for carbon sink. Until now, as the timber is apt to be rotten quickly and eaten by worms, it has lost out to concrete in the construction market. But the fact that it is easily rotten can be interpreted as little burden to the nature environment, then it is again considered as an advantage. Because it returns to the nature after being used, so it doesn't burden to the environment. Therefore, for this reason, the fields of construction and civil engineering must actively utilize many structures using timbers. In Korea, as a part of the river development, it is being developed to store carbon in a timber for a long time, overcoming the problem of timber's easily rotten character, which has been difficult for most nations to find a solution. The principle of the technology is in that a timber in water isn't easily rotten. All rotting fungus that rotten timbers are aerotropism, so the fungus can't live without air. But in water, as the supply of air is blocked, they can't act. Therefore in water, a timber can be preserved not being rotten at least for more than 200 years. If we raise a tree for 50 years, use its timber for another 50 years, and returns it to the nature, the way will not be helpful for our Earth environment. But if we use a timber for 200 years after raising it for 50 years and return to the nature, it will absolutely be very helpful to the Earth. This is the best way to extend the cycle of carbon circulation. In making ecofriendly river, if riverbed using tinned timbers is constructed, the stored carbon volume for harvested timbers can be increased without any limit. In terms of economic advantages, a timber in water doesn't have to be dried, and can be used as a live tree. Another advantage is that it can be used with no preservative treatment. One ton of tinned timbers can construct about 5m3 of riverbed. Our expectation to the tinned timber is very big because it enables to protect the ecosystem in a river and to make aquatic space with rich variety of species. Therefore timber-riverbed is like to manage “A Forest in a River”. Because efficiently utilizing the products out of cultivating a forest can be a way to fostering sound, energetic woods, and an important preparing measure in terms of the formation of 21st Circulating Society, I intend to introduce the technology of timber riverbed.
Dong-heub Lee, Won-Joung Hwang
Laboratory test to determine the effect on durability of combining biobased building materials with timber in construction
2017 - IRG/WP 17-20604
The use of Structural Insulated panels is a construction approach that is seeing more abundant use and is becoming a widely available method. Preformed units are usually a composite structure which often include a range of bio-based materials such as timber, wool or straw. Traditional laboratory based wood decay tests do not take into account this combination of biobased materials and it may be possible that non wood materials such as plant or animal fibre insulation could influence the durability of adjacent wood elements by synergistic mechanisms. One method may involve the insulation material acting as a moisture reservoir or moisture buffer for wooden structural elements with a consequential effect on their durability. This paper details an experimental approach to determine if there could be such an effect, using a modified form of existing wood decay testing methods. The test utilises an agar jar approach with a pad of fibrous insulation e.g. wool or hemp placed between the inoculated agar and a wood block. Results show the effects of the type of insulation used on the moisture content and decay of the test blocks. It is shown that moisture was able to pass through the insulation to varying degrees to be absorbed by the wood blocks. Fungal mycelium was then able to grow through some of the insulation materials to attack the wood. The test show that wool for example appeared to hold water away from the wood samples and reduced subsequent decay. Hemp however, did not prevent water access to the wood blocks and in fact enhanced decay of the blocks.
S F Curling, G A Ormondroyd
Solvent drying and preservation of timber
1977 - IRG/WP 381
Processes which combine drying and preservation are first reviewed. Some preliminary experiments are then described in which blocks of green Sitka spruce sapwood were immersed, in a solution of tributyltin oxide (TBTO) in methanol at 60°C. Satisfactory penetration of the preservative and exchange of methanol and water occurred in a few hours. The methanol was removed rapidly from the wood by evaporation. Satisfactory penetration of TBTO into initially methanol-saturated samples occurred in a similar period. The factors influencing. such treatments are discussed. High initial moisture content of the wood and a high operating temperature are particularly desirable. Some aspects of the possible commercial operation of the process are discussed.
J A Petty
Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providing up 90% control at a concentration of 2.5%. A potential alternative, Stopstain a borate-based chemical, gave results only slightly better than the untreated control timber, at a concentration of 5%. Unless the environmental cost and toxicological hazards of traditional chemicals are highlighted the newer and safer chemicals will be reluctantly accepted by industry as they are regarded as being prohibitively expensive.
A J Masuka
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 2: Report of treatment and installation in Australia
1978 - IRG/WP 440
The purpose of this test and the procedures to be followed have been fully set out in documents distributed by the International Research Group on Wood Preservation and numbered IRG/WP/414 and IRG/WP/420. The prescriptions set out in these two documents have been closely followed.
Manual of a mini treating plant for waterborne preservative treatment of timber and bamboo
1999 - IRG/WP 99-40130
This contributional article includes machinaries and equipments necessary for a small wood treating plant for the pressure treatment of tim bers with waterborne preservatives along with the cost and design. The preservative treatment limitations, treatment schedules and specifications for different products have been described. The cost of a mini treating plant will be 6,00,000 Tk. (13,000 US$), suitable for preserving timber and bamboo products for indoor and outdoor uses and will out last teak wood. The additional durability of timber and bamboo will create economically and environmentally safe conditions.
A K Lahiry
Field performance of wood preservative systems in secondary timber species
1997 - IRG/WP 97-30152
The objective of this ongoing study is to evaluate the performance of new, potential, and standard wood preservative systems in secondary North American timber species. Eleven preservative systems were evaluated in this study - ACQ Type B, Copper Citrate 2: l, CDDC, chlorothalonil/chlorpyrifos, copper-8-quinolinolate, tebuconazole/chlorpyrifos, RH287, propiconazole/chlorpyrifos, copper naphthenate, CCA. and creosote. Field evaluations are being performed with ground contact field stakes and termite-specific testing in Hawaii, along with laboratory soil bed tests. The major wood species used with all the systems and evaluation methodologies are loblolly pine, northern red oak, tulip poplar, and cottonwood. More limited evaluations (field stakes only) are being conducted with eastern hemlock, red maple, and sweetgum. Information is presented from laboratory soil bed, field termite, and field stake evaluations. There is good correspondence between soil bed and field stake results. The more highly developed preservative systems and those in an AWPA P9 Type A oil carrier tend to perform better, and there can be a strong affect on performance from the wood species.
P E Laks, K W Gutting, R C De Groot
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. 2nd Interim Report
1981 - IRG/WP 477
Three reference wood species - Alstonia scholaris, Fagus sylvatica and Pinus sylvestris, untreated and treated with 3%, 6% and 10% CCA and CCB solutions were supplied to all participants for submergence at local sites. Regular examination of samples is being carried out - 6 months, 12 months and then annually for 7 years.
R A Eaton
Report an some aspects of forest and the timber preservation in Fiji 1999
2000 - IRG/WP 00-40189
This report is divided in two sections. One is the general description of some aspects of the Forest indicating timber availability in Fiji. The other Section is an "Status of Timber Preservation in Fiji in 1999".
S D Kumar
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 10 from Naos Island, Panama
1980 - IRG/WP 462
Blocks of 3 wood species, Beech (Fagus sylvatica), Scots pine (Pinus sylvestris) and Alstonia (Alstonia scholaris) were exposed at site number 12 at Naos Island, Panama on March 8, 1978 by John R. DePalma. The arrangement of the panels in the exposure site is as shown in Figure 1.
D W French
Electrodialytic remediation of creosote and CCA treated timber wastes
2002 - IRG/WP 02-50190
There is a growing concern about the environmental issue of impregnated timber waste management, since an increase in the amount of waste of treated wood is expected over the next decades. Presently, no well-documented treatment technique is yet available for this type of waste. Alternative options concerning the disposal of treated wood are becoming more attractive to study, especially the ones that may promote its re-use. Inside this approach, the electrodialytic process (ED) seems a promising technique for removal of preservative chemicals from treated wood waste. The method uses a direct electric current and its effects in the matrix as the “cleaning agent”, combining the electrokinetic movement (mainly due to electromigration, but also electro-osmosis and electrophoresis), with the principle of electrodialysis. This work reports results from the application of the electrodialytic process to an out-of-service Portuguese creosote and CCA-treated Pinus pinaster Ait. railway sleeper and pole. The behaviour of the process is described and the main results discussed. The average removal rate, estimated in accordance with prEN 12490, for creosote from treated timber waste was around 40 %.. For CCA treated timber waste, experimental conditions that could optimise the process efficiency (e.g. current density, time) were studied. The highest removal rates obtained until now, in our studies, were 93 % of Cu, 95 % of Cr and 99 % of As for sawdust using 2.5 % oxalic acid (w/w) as the assisting agent. For CCA treated wood waste in the form of chips, the best removal rates obtained until now were 84 % of Cu, 91 % of Cr and 97 % of As.
E P Mateus, A B Ribeiro, L Ottosen
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 13: Report of fourth inspection (36 months) in Australia
1981 - IRG/WP 481
This report presents the results of the fourth inspection of the IRG/COIPM International Marine Test specimens installed in Sydney Harbour in December, 1977. The inspection took place on 9th December, 1980, after 36 months exposure. Full details of the treatment and installation of the specimens, as well as results of the first three inspections (after 6, 12, and 24 months exposure), have been presented in earlier reports. All inspections of this test have been carried out in accordance with the Working Plan (see IRG/WP/414) except for an X-ray examination of the specimens. This facility is not available at the test station. In conformity with the provisions of the Working Plan, the fifth and sixth replicates of the whole test (i.e. those specimens with '5' or '6' as the final digit of their serial number) were recovered and returned to the United Kingdom after 6 months and 24 months of immersion. Thus, only four replicates remain to be examined at this and ensuing inspections.
The biostatic effect of copper on decay of fire retardant-treated mining timber
1991 - IRG/WP 1507
Blocks of Eucalyptus grandis were treated with 20kg/m³ ammonium sulphate as fire retardant and challenged with Coriolus versicolor. Replicates were soil buried. A second set of blocks was treated with retardant and copper at 6.6 kg/m³ (ie 1% w/w), and challenged similarly. After 8 weeks weight losses produced by Coriolus versicolor in untreated, retardant treated and copper supplemented blocks were 45, 25, and 0% respectively, and corresponding weight losses in soil were 27, 25 and 10%. These results, and electronmicroscopical observations, showed conclusively that Eucalyptus grandis treated with fire retardant was rapidly decayed, and that copper inhibited such decay.
G D Shelver, E A Shelver, A A W Baecker
Observations on the colonization of freshly-felled timber treated with prophylactic chemicals by mould and sapstain fungi
1989 - IRG/WP 1394
Field tests using freshly felled pine sapwood were set up to determine the effectiveness of a range of antisapstain compounds and to study the problems of colonization by mould and sapstain fungi. Differences were recorded both in the overall performance of the compounds and also their selectivity in controlling specific fungal types. These results were found to be useful in gaining a better understanding of biocide - fungal interactions.
G R Williams, D A Lewis
An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper-chrome-arsenic preservative
1981 - IRG/WP 3150
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. We have evaluated the influence of steaming on treatability with a waterborne CCA preservative.
C R Coggins
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 8: Panama test results
1980 - IRG/WP 458
Summary of damage to ITRG test stakes by pholadidae and teredinidae at the Panama test site - 8 Mar. '78 to 11 Oct. '79
J R De Palma
Boron treatments for the preservation of wood - A review of efficacy data for fungi and termites
1994 - IRG/WP 94-30037
Boron treatments have been used for many decades for protection of timber from biological attack and also as a fire retardant treatment. In recent years there has been an increased interest in boron treatments as an option for protection of structural timbers' e.g. timber framing used in termite risk areas. This paper reviews efficacy data for both fungi and termites relevant to this end-use.
J A Drysdale
Conforming to european standards for preservative-treated timber: Specifying with confidence
2000 - IRG/WP 00-20194
A four-year collaborative study between four industrial partners and BRE has assessed timber treated by current UK industrial practices in the light of current European Standards. Data were collected for CCA and creosote treated timber components, and compared with the requirements laid out in EN351-1 and -2. A number of difficulties were encountered that have been described in previous IRG papers (98-20150, 99-20156), such as the poor reproducibility of chemical analyses and variable timber density. This paper describes the conclusions of our collaboration, focusing on the application of the findings and how to overcome any difficulties encountered. The data collected allowed the calculation of figures that have been submitted for inclusion into the UK's proposed national code for preservative-treated timber (DD239). An example is the recommendation of new minimum retention figures for creosote-treated commodities. This paper describes the factors that will enable UK specifiers to use the European Standards with confidence and greater understanding of how they map onto traditional methods of specification. In addition valuable lessons have been learnt applicable to the industry world wide.
E D Suttie, R J Orsler
On site test for indicative determination of leaching of components of preservatives from treated timber. Part 2: New data on CCA-C, CC and CCB treated timber
1994 - IRG/WP 94-50025
The 'on site test' was published at the IRG meeting in Cannes in February 1993 (IRG/WP 93-50001/12). Since this publication many on site tests were performed parallel to so-called shower tests. The correlation between the test results of the on site tests and the shower test has been established more clearly. For chromium the correlation between both tests is indistinctive of preservative formulation. For copper the correlation differs for CCA on one side and CC's and CCB's on the other side. In some cases the on site test does not correcty predict shower test results. The reasons for this phenomenon are discussed. It can be concluded that the on site test is a roughly indicative test for assessing the leaching of components of preservatives from treated timber. The correlation figures, however, are formulation dependent.
W J Homan