Your search resulted in 422 documents. Displaying 25 entries per page.
Re-use of casting timber
2011 - IRG/WP 11-50283
Re-use of casting timber could be a way of saving timber resources, particularly in countries where most timber for construction purposes has to be imported. The objective of the present study was to investigate residual concrete on casting timber re-used five times. Moulds were made of sections of Norway spruce, untreated and treated with a casting oil and a wax formulation applied by a vacuum-pressure process, respectively. Casting was carried out with concrete of strength class C40/50 with a slump of 120 mm. The concrete was allowed to set for at least ten days before the sections were investigated with respect to residual concrete. None of the treatments, wax applied by vacuum pressure treatment or casting oil applied by brushing, resulted in completely residual free wood surfaces after five castings. The best result was obtained with the casting oil. If application by vacuum-pressure ever shall be an attractive alternative to the superficial treatment with casting oil, further improvements of the treatment formulation are necessary. It is hardly realistic to completely avoid residues, but re-use of the casting timber five times should be possible if the residues can be minimized and some scraping can be accepted.
I Johansson, S Breyne, H Egnell, J Jermer
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
Recycling of pressure impregnated timber and preservatives - incineration techniques
2001 - IRG/WP 01-50166-19
The object of the recycling research projects is to determine the technical and economical requirements of the recycling of CCA-impregnated wood. In the first recycling of impregnated timber project the amount and location of recyclable treated wood in Finland was determined and the costs of recycling were calculated. An incineration test was also made (1998). The conclusion of the first project is that it is possible to design a full scale plant for burning CCA-treated wood, to treat condensate water, to purify the gases using a very effective method, and to treat the ash in a copper smelter. The object of the second recycling research project in Finland is to determine the technical and economical requirements of incinerating CCA-impregnated timber so that an investment decision can be taken on whether to build an incineration plant. Thus far in the course of the second project a trial has been established for collecting impregnated sawn timber at waste treatment plants and for cleaning the material of large metal constituents. The first part of the incineration trial was carried out in November 2000 and this will continue in the spring of 2001, after which an interested investor can reach a decision on a possible investment.
T Syrjänen, E Kangas
The identification and preservative tolerance of species aggregates of Trichoderma isolated from freshly felled timber
1992 - IRG/WP 92-1553
The surface disfigurement of antisapstain treated timber by preservative-tolerant fungi remains a major problem in stored timber. Identification of a range of isolates of Trichoderma based on microscopic morphological characteristics was found to be imprecise due to the variable nature of this organism. In addition, studies to compare visual (morphological) characteristics of these isolates with their tolerance to the antisapstain compound methylene-bis-thiocyanate (MBT) using minimum inhibition concentration (MIC) tests showed no clear correlations. Isoenzyme electrophoresis was used to investigate the taxonomic relationships between species aggregates of Trichoderma isolated from antisapstain field trials and to identify physiological differences between 30 isolates of Trichoderma which show tolerance to MBT at concentrations ranging from less than 4 ppm to 34 ppm. Results indicate that there is considerable variability in the preservative tolerance of different Trichoderma isolates from particular locality. This highlights the need for field testing of an antisapstain compound in the same locality and under the same conditions in which it will be used in practice.
R J Wallace, R A Eaton, M A Carter, G R Williams
Light organic solvent preservative treatment of glue-laminated radiata pine
1986 - IRG/WP 3380
The high permeability of radiata pine (Pinus radiata D. Don) is associated with ray-tissue and in particular the cross-field pits linking ray-tissue to tracheids. This pathway is absent in the tangential grain direction, leading to poor preservative penetration when treatment is restricted to the radial face - for example, timber fabricated into glue-laminated beams.
Blue stain in timber in service. Results of co-operative tests to compare different artificial weathering systems 1981-82
1983 - IRG/WP 2193
The paper describes results of the third phase of co-operative laboratory experiments comparing the effects of different artificial weathering systems on chemicals to control blue-stain in service. Atlas, Xenotest and Marr equipments are shown to give essentially the same results for 5 of the 6 chemicals tested.
A F Bravery, D J Dickinson
A survey to assess the current and future usage of timber in British port structures
1998 - IRG/WP 98-10247
Port engineers responsible for 30 British ports were surveyed by questionnaire or interview to establish current and prospective usage of timber in those ports. The ports surveyed account for about 25% of total cargo handled annually in Britain and being located all around the British mainland, were considered to form a representative sample. The survey identified the hardwoods and softwoods in use for various applications in port structures, the criteria for selecting materials for these structures, the materials considered most suitable for piles and fenders and the types of preservative specified. Additional data was collected on the current condition of structures, incidence of marine borers, experience and training of port engineers and their attitude towards timber.
G S Sawyer, S E M Plaster
Utility, deterioration and preservation of marine timbers in India
2005 - IRG/WP 05-40314
Timber is extensively used in India in the marine environment for various purposes due to its several advantages over modern materials. Infact, its use is increasing in recent years, finding wider and wider applications and this scenario is not going to change in the near future. Though, the bio-deterioration problem is found very severe in tropical waters, still indigenous methods are widely employed for the protection of fishing craft and the present level of chemical treatment is well below 5% of total timber used. This is due to socio economic problems of the potential timber user groups, unavailability of treatment plants in the coastal areas, lack of awareness in user groups, etc. In this paper, types of fishing craft used in the country, timber uses in the marine environment, bio-deterioration losses, research conducted on bio-deterioration aspects at various places and methods applied for the protection of wooden structures are presented.
B Tarakanadha, M V Rao, M Balaji, P K Aggarwal, K S Rao