Your search resulted in 27 documents. Displaying 25 entries per page.
The performance of metal-chromium-arsenic formulations after 32 to 38 years' in-ground exposure in Australia
2000 - IRG/WP 00-30240
Two trials of metal-chromium-arsenic preservatives were exposed in-ground in Australia. In Trial 1, Pinus radiata stakes treated with Boliden K.33, Boliden S.25, Celcure A, Tanalith C and Tanalith CA were installed at Sydney and Narrandera in 1961/1962. In Trial 2, P. radiata and Eucalyptus regnans sapwood were treated with Celcure A, Celcure A21-N, Celcure A 21-O and Tanalith CA (new) and installed at Sydney and Innisfail in 1966/1967. In Trial 1, all metal-chromium-arsenic preservatives at 8 and 12 kg m-3 gave median specimen lives in excess of 35 years. As none of the stakes treated to 12 kg m-3 with Boliden K.33, Celcure A, Tanalith C or Tanalith CA had become unserviceable, the minimum guarantee period for these preservatives is greater than the present exposure periods. In Trial 2, the four CCA preservatives when impregnated into P. radiata sapwood at 12 kg m-3 gave median specimen lives at Sydney of greater than 32.5 years. With E. regnans sapwood treated to 12 kg m-3, only Celcure A 21-0 gave a median specimen life at Sydney of greater than 32.5 years. At the high decay and termite hazard site of Innisfail, Celcure A 21-0 protected the eucalypt better than any of the other CCA formulations.
G C Johnson, J D Thornton, J Beesley
Soft rot in CCA-treated utility poles in Sweden
1989 - IRG/WP 1398
Soft rot investigations of CCA-treated utility poles (Pinus sylvestris L.) have been conducted throughout large parts of Sweden during 1974-1985. The investigation included 179 utility poles of the State Power Board which had been used for 10-18 years in the different administrative regions from northern to southern Sweden. In addition, 193 telephone poles from the Östersund area and 218 from the Kristianstad area were studied after having been in use for 18-25 years. The soft rot fungi cause two types of attack in wood cells, namely cavities (Type I) and erosion (Type II). In this investigation, soft rot is reported only when cavities of Type I were found. Erosion (Type II) is more difficult to observe, particularly in early stages, and in addition is almost impossible to distinguish from certain other attacks of rot, such as white rot, which may have occurred during storage of the poles before impregnation. In western and central Sweden, minor attacks of soft rot were found after 10-12 years in State Power Board poles embedded in soil in arable land and meadows. Power Board poles in northern Sweden had minor attacks of soft rot after 16-18 years in arable land and also in forest land when embedded in soil. Poles used by the Telecommunications services, all embedded in stone, showed minor and only occasional attacks of soft rot at Östersund (northen Sweden), but considerably more soft rot at Kristianstad (southern Sweden). The Telecommunication poles had been in service up to seven years longer than the poles used by the State Power Board. The localization and spread of soft rot attacks in a pole can vary. There may be many reasons for this, including insufficient impregnation, leaching, etc. The soft rot attacks found in the Power Board poles are always minor and sporadic and none of the investigated poles can be said to imply any safety risk. The same applies to the Telecommunication poles at Östersund whereas those at Kristianstad demonstrated considerably more severe and more frequent attacks. The attacks of soft rot in the Telecommunication poles more frequently occurred internally, more often deeper in the sapwood than in the outermost parts.
H Friis-Hansen, H Lundström
Collaborative experiments in testing the toxicity of wood preservatives to soft rot fungi
1970 - IRG/WP 25
Eight Institutes from seven countries, Austria, England, France, Germany, Holland, Sweden and Switzerland have collaborated in an attempt to assess the suitability of various laboratory test procedures for acceptance as standard methods of determining the toxicity of wood preservatives to the cellulose-attacking micro-fungi which cause 'soft rot' of wood. Pure culture methods with Chaetomium globosum have been tested together with soil burial methods in which the mixed fungus flora of unsterilised local soils has been used as inoculum. The results obtained with a copper/chrome/arsenate preservative have been presented and discussed. It is concluded that the information available is not yet adequate to permit definition of a reliable standard test method. The work has however demonstrated the unsuitability of Chaetomium globosum as a test organism in pure culture tests on softwood and has given indications that soils low in organic matter content may be most suitable for mixed culture tests.
J G Savory, A F Bravery
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 used.
F G Evans
Abstracts of some papers promised for IRG 25
1994 - IRG/WP 94-60022
The biocides directive
1995 - IRG/WP 95-50040-25
Report of the meeting of the refractory timbers sub-group, Lappeenranta, Finland on 25 May 1989
1989 - IRG/WP 3561
The first meeting of this sub-group took place on Thursday 25 May and considered the following agenda: 1) Papers presented to the meeting "Performance of treated spruce in Canadian field test sites" by J.P.Hösli and E.E.Doyle, IRG/WP/3506 and "Performance of CCA treated spruce and pine in unsterilized soil" by A.J.Nurmi. 2) Future work areas for the sub-group 3) Membership of the sub-group 4) Circulation of information
R J Murphy
Abstracts of some papers and posters promised for IRG 25, Part 2
1994 - IRG/WP 94-60034
Preservación de maderas en Bolivia
1986 - IRG/WP 3360
Este documento ofrece datos generales concerníentes a los recursos forestales de Bolivia, las facilidades existentes para preservación de maderas, la investigación y educación en esa materia. Se proporciona información sobre instituciones vinculadas a la actividad y las perspectivas del tratamiento de maderas en el país.
A S Viscarra
The internal-external diffusion process: Table salt treated poles
2005 - IRG/WP 05-50224-25
This new technique of preservation of wooden poles consists of keeping preservative in stock, in a reservoir drilled inside the pole, in its whole length. This permits the use of non toxic, common products such as table salt, grease, etc, in the preservation of utility poles, building columns, or the like. Some major obstacles to a good implementation of a good preservation with the classical processes become advantages with the new technique, notably the low permeability of some sorts of wood, and inaptitude to the fixing of a big number of chemicals aimed to provide a durable protection to wood submitted to weather.
Performance of chromated copper arsenate-treated aspen fence posts installed in Forintek's Eastern test plot from 1951 to 1963
1984 - IRG/WP 3272
Aspen poplar fence posts were pressure treated by the full cell process using three formulations of copper chrome arsenate wood preservative. A total of one hundred and fifty nine of the posts were installed in service in Forintek's Chalk River post plot from 1951 to 1962. During the 1982 general inspection of the post plot all 159 posts were still in service. A groundline inspection was carried out on the material to determine the extent to which decay had progressed during this period. Samples were taken from the surface of tanalith C treated posts and subsequent microscopic examination revealed that soft rot attack was present in the outer portion of posts. The groundline area of posts treated with (K 33), CCA type B and (greensalt) CCA type A were in generally good condition after 22 years and 31 years respectively. Rate of decay was highest for CCA-C tanalith treated posts at 0.3 mm per year with a retention of 3.04 kg/m³ oxides.
C D Ralph
An interim report on trials with 'Boliden K33' and 'Celcure A' in water of different salinities in the Baltic Sea and in the UK
1974 - IRG/WP 406
It was felt necessary to undertake field trials using large test samples exposed in natural water of different salinity in order to determine preservative leaching and to assess the degree of biological attack.
R A Eaton, D J Dickinson
IRG 25 invitation
Copper based water-borne preservatives: The use of a thin section technique to compare the protection of wood by copper based preservatives against soft-rot and bacterial decay
1987 - IRG/WP 2286
This paper describes the techniques developed and gives examples of results obtained for the performance of copper based wood preservatives against both the bacterial and fungal hazards.
A M Wyles, D J Dickinson
Evaluation of fungal remediation of creosote treated wood
1998 - IRG/WP 98-50101-25
Biotechnological remediation of creosote treated wood may be of interest in connection with novel recycling processes. White rot fungi and/or their ligninolytic enzyme systems are supposed to be valuable tools for such processes. This paper reports about results achieved when creosoted wood was treated in solid substrate fermentation with selected white rot fungi after different extraction procedures. None of different optimized fermentation conditions enabled the colonization of creosoted wood. The minimal inhibitory concentration for fungi was found to be about one power of ten below the actual concentration in railway sleepers. The efficiency of various solvents to extract creosote below the MIC for fungi was investigated. When 16 PAHs were analysed by HPLC under growth conditions, the best fungal strain degraded 100% of the low molecular weight PAHs and 92% of the 4-5 ring PAHs after 16 days. The lowest reduction was found to be 79% for benzo(b)fluoranthene. The results are discussed with respect to the application of white rot fungi for technical processes in combination with novel recycling methods for creosote treated wood.
K Messner, S Böhmer
Treatability of waterstored poles of Norway spruce by sap-displacement and pressure treatment with Boliden K33 and creosote
1973 - IRG/WP 328
Poles of windthrown Norway spruce were stored in bark under water sprinklers for 11-20 months or fully submerged in a lake for 3 years (tab. 1 and 2). Water content after storage is shown in fig. 1 and 8. Treatment with Boliden K33 by sap-displacement (open tank suction) gave a poor result. The Danish requirements of delivery claim a penetration of 20 mm and a net retention of 12 kg/m³ in outer 20 mm sapwood. According to that 22% of the poles stored for 11 months, 53% of those stored for 20 months under water sprinklers and 67% of those waterstored for 3 years were rejected compared with 11% in both control series (tab. 3 and 4). There was no correlation between water content in outer sapwood before treatment and penetration/retention neither for stored nor for unstored poles (fig. 2-7 and 9-10). Pressure treatment (full-cell) of water stored poles with Boliden K33 after air-drying to app. 28% gave a similar poor result (tab 5) while pressure treatment (Rueping) of water stored poles with creosote gave very good penetration as well as retention (tab. 6). The hypothesis is put forward, that the main reason for the unsatisfactory result of the treatment with Boliden K33 might be coagulation of the bacterial slime when mixed with the salt blocking the pathways for the liquid, although the membranes in the tori and the parenchymatic cells are supposed to have been partly destroyed by the bacteria.
P Moltesen, E Borsholt, B Bang
Corrosion of fasteners in treated wood
1971 - IRG/WP 303
Surveying tests for determining the corrosion rates of some metals and alloys in wood untreated as well as treated have been made. It is shown that ordinary steel corrodes faster than other common fastener metals such as copper, brass, aluminium and stainless steel do. Zinc coatings, however, will prevent the steel corrosion effectively provided that the coatings are thick sufficiently. Catalytic decomposition of cellulose by rusting iron is briefly discussed since the expectation of life for a fastener joint is not only depending on after the corrosion remaining cross-section of the fastener but also from the wood deterioration.
Scandinavian experience – 25 years’ experience in transforming used creosoted wood into bio-fuel
2005 - IRG/WP 05-50224-18
Swedish experiences show that the best and most efficient way to handle the creosoted wood waste is through combustion. The preparation of creosoted waste wood to fuel chips at IQR AB’s plant in Trollhättan is done by splinting the wood according to a special method. Mainly railroad sleepers, but also other wooden commodities, from all over Europe are delivered to the plant. The wood material is crushed in a number of steps to achieve the appropriate size of the chips. The wooden chips are then delivered to combustion facilities in Sweden. The PAH emissions can be kept at a low level due to good mixing, high temperature and a high retention time in the furnace.
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative concentration and temperature. For interpretation of experimental data the effect of these factors is discussed in the light of the chemistry and the mechanism of fixation of CCA preservatives. For a proper handling of the treated timber, knowledge of the duration in actual working conditions is essential.
The fate of salt preservatives in facility yard soils and decontamination of soils and drainage waters
1993 - IRG/WP 93-50001-25
Extensive studies during the past 10 to 15 years revealed that noticeable amounts of preservative components may be released in the environment by dripping off or by rain prior to fixation unless adequate precautions are taken. Therefore, soil and groundwater contamination especially from chromium-VI compounds but also from other inorganic and organic constituents exist in impregnation plants, possibly endangering the soil and groundwater ecosystem. The actual risk potential originating from chromium-containing wood preservatives in a practical situation are to be studied in the frame of a comprehensive research programme sponsored by the German Ministry of Research and Technology (BMFT). Accompanying laboratory investigations are performed with the aim of assessing the various types of water-soluble wood preservatives with respect to whether or possibly which compounds remain mobile und thus bio-available in the soil. Special attention is drawn to the question as to which effective constituents are adsorbed to soil particles depending on the mineralogical-geological composition of the soil, and at what situation the retention capacity for effective components of different soils would be exceeded. The results of the pilot study and of parallel running laboratory tests serve as a basis of deterioration analyses for grading and assessing the endangering potential in the ecosystem and shall provide a basis for the choice of adequate remedial concepts and measures to avoid such environmental impacts.
R-D Peek, H Klipp, K Brandt
Leaching from field test stakes. Part 2: The distribution in and leaching from different parts of test stakes
1994 - IRG/WP 94-50026
Field test stakes treated with Boliden K33 (copper, chromium and arsenic) and Cuprinol Tryck (CT86) (copper and N-alkylbenzyldimethylammoniumchloride) respectively were exposed in ground contact at two different test fields in Sweden and rejected due to decay after 2 to 28 years. Stakes treated with the same preservatives were also exposed during 7 years above ground. The test stakes have been analysed regarding remaining preservatives in different parts of the stakes. As a reference, unexposed stakes were analysed regarding retention and gradient of the two preservatives in the stakes. There was a gradient in the concentration of preservatives in the unexposed stakes, the gradient being greater for CT86 than for CCA. The remaining preservatives in stakes treated with CCA and CT86 differ depending on preservative used and how they were exposed in the field. Least preservative was found in the end grain and there was an indication of a redistribution of preservatives from the inner part of the stakes to the outer part. Leaching from stakes exposed horizontally above ground was not less than that from stakes in ground contact.
F G Evans, B Nossen, M-L Edlund
Resistance of acrylic paints on wood against growth of the rot fungus Dacrymyces stillatus
1990 - IRG/WP 2345
In the last few years the presence of the rot fungus Dacrymyces stillatus has been repeatedly confirmed in external wood panels, particularly from wood painted with water based paints. A laboratory method for testing of the fungal resistance of paint films on wood has been developed.This method has been used to test the efficacy of the fungicides Parmetol DF 18 and Parmetol HF 25 against attack by Dacrymyces stillatus. Recent findings regarding factors of importance for fungal attack of painted wood are also discussed.
Soft rot test of copper/chrome/arsenic treated heartwood of three Malaysian timbers by the vermiculite-burial method. (+ correction document of 25 July 1990)
1990 - IRG/WP 2354
Heartwood of copper-chrome-arsenic (CCA) treated kempas (Koompassia malaccensis), tualang (Koompassia excelsa) and keruing (Dipterocarpus spec.) was found to be susceptible to soft rot in recent pole surveys. Standardized heartwood blocks were impregnated with 0 to 6.3% (w/v) CCA and challenged to decay for twelve weeks by a mixed inocula of Chaetomium globosum, Glenospora graphii, Humicula grisea, Petriella setifera and Trichurus spiralis in containerized vermiculite-burial decay system. Fixation of CCA in wood immediately following impregnation took place by steaming (110°C, 1 h) or by slow drying (4 w), and half of both were leached (CEN 84). A similar burial test using soil was included for comparison. Average% mass loss (ML) in treated keruing was generally <3% with no clear differentiation among CAA levels, methods of fixation with or without leaching and decay methods. A relatively gradual-to-abrupt increase in resistance with higher levels of CCA was found for kempas and tualang, where average ML of the untreated samples for each combination of fixation/leaching was between 5 and 9% (inoculated vermiculite) or 3% (unsterile soil) with negligible decay at concentrations of about 2% CCA and above. The suitability of such soft rot tests with treated heartwood is discussed.
R-D Peek, A H H Wong
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 4: Conversion reactions during storage
1974 - IRG/WP 332
Precipitates simulating those produced in wood by preservative fixation reactions were prepared by the reduction of Boliden K 33 and Celcure AP solutions with hydrogen peroxide and hydrazine. The pH changes on aging at 20 and 50°C were studied and related to the chemistry of fixation previously described. Hydrolysis of copper arsenates may render arsenic acid temporarily water soluble pending precipitation by trivalent chrome liberated by the slow hydrolysis and reduction by wood of chromic chromates. As the reduction of chrome is the primary driving force for the fixation of Cu-Cr-As preservatives, pH changes were observed in sawdust treated with dilute CrO3 solutions under different temperature cycles. The pH is essentially independent of temperature during the first three days when chromic chromates are being formed, but the subsequent pH is highly temperature-sensitive. Part of this effect is due to hydrolysis and reduction and part to generation of acidic reaction products in the wood at higher temperatures.