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A comparison of soft rot, white rot and brown rot in CCA, CCP, CCF, CCB, TCMTB and benzalkonium chloride treated Pinus radiata IUFRO stakes, after 9-15 years exposure at five test sites in New Zealand
1991 - IRG/WP 1485
The aim of this study was to determine if decay type varies significantly between five field trial test sites of different soil type, aspect and climate in 9-15 year old, replicate CCA, CCF, CCP. CCB, TCMTB and AAC treated IUFRO stakes. A visual on-site assessment of decay type on every test stake was made and observations confirmed by microscopical examination. Regression analyses were used to determine significant differences of percentage frequency of occurrence of each rot type between sites and preservatives. Large differences in percentage frequency of occurrence of rot type were evident between sites. One site was dominated by brown rot (85%) and two were dominated by soft rot (99 and 91%). The fourth site had intermediate proportions of brown rot (40%) and soft rot (71%) but had the second highest occurrence of white rot (32%) (highest = 37%; lowest = 11%). The fifth site was distinct in that a large proportion of stakes (69%) had both well established brown rot and soft rot. Stakes at the other four sites tended to have only one rot type. Some highly significant preservative effects were also found. Possible causes of these differences are discussed in terms of inter-site soil type, climate and other differences.
R N Wakeling
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 treated posts smouldered until destruction of the majority of the posts occurred. Posts treated with CCA-oil took longer for destruction to occur than posts treated with CCA-C or CCA-wax. Creosote treated posts and untreated controls did not show prolonged smouldering and consequently were not destroyed by the burning test, although their strength was reduced. A high fuel load increased the time that posts were alight and smouldering, and for CCA treated posts decreased their time to destruction.
P D Evans, P J Beutel, C F Donnelly, R B Cunningham
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
Types of decay observed in CCA-treated pine posts in horticultural situations in New Zealand
1984 - IRG/WP 1226
The few reported failures of 11-12-year-old horticultural posts in New Zealand in 1982 were caused by brown-rot. A subsequent survey of CCA-treated posts in all the major horticultural areas has revealed decay of many posts. A microscopic examination of these posts has shown decay by brown-rot, white-rot, soft-rot and bacteria. Several types of bacterial decay have been observed.
J A Drysdale, M E Hedley
Fungal and bacterial attack of CCA-treated Pinus radiata timbers from a water-cooling tower
1991 - IRG/WP 1488
Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells. The extent of damage to wood cells due to microbial activity varied, combined fungal and bacterial attack having the most damaging impact.
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh
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
Progress towards controlling soft rot of treated hardwood poles in Australia
1977 - IRG/WP 289
Termite resistance of pine wood treated with chromated copper arsenates
1997 - IRG/WP 97-30128
Two four-week, no-choice laboratory tests were performed with CCA-treated southern yellow pine and radiata pine against Formosan subterranean termites, Coptotermes formosanus. CCA retentions as low as 0.05 kg/m3 (0.03 pcf) provided protection from all but light termite attack (rating of 9 on a 10-point visual scale). Similar and consistent light attack on wafers containing retentions as high as 6.4 kg/m3 (0.4 pcf), coupled with complete termite mortality, demonstrates that the mode of action of CCA treatments relies upon toxicity rather than having any repellent effects against termites.
J K Grace
Application of radio frequency heating to accelerate fixation of CCA in treated round-wood
1999 - IRG/WP 99-40133
The potential of radio frequency heating to accelerate the fixation of chromated copper arsenate (CCA) in treated round-wood was assessed. Pre-dried Douglas-fir and western red cedar round-wood sections were pressure treated with CCA in a pilot plant retort, after which they were placed individually in a pilot radio frequency (RF) chamber. Based upon the color reaction of chromotropic acid with hexavalent chromium and the quantitative assessment using diphenyl carbazide, fixation was achieved in less than 6 hours. During heating, the temperature at various locations inside the pole sections was monitored by fiber-optic thermocouples. The moisture profiles before, and after fixation, were also recorded. Further studies will examine other benefit of RF heating, including a) sterilization, and b) rapid drying of round-wood with minimum check formation.
Fang Fang, J N R Ruddick
Field trials of groundline remedial treatments on soft rot attacked CCA treated Eucalyptus poles
1983 - IRG/WP 3222
A total of 17 CCA treated Eucalyptus poles, which were found to contain 2-5 mm of soft rot in October, 1980, were reinspected in October, 1982. In 1980, 11 of the poles were given a supplemental groundline bandage treatment of either Osmoplastic or Patox, while 6 of the poles were designated as untreated controls. Two years after remedial treatment, samples were removed from the poles for microscopic observations and for chemical retention analysis. It was found that the remedial bandage treatments were effective in preventing any further advance of soft rot. Based on the positive results of this study, a treatment efficacy of five years or longer is predicted.
W S McNamara, R J Ziobro, J F Triana
Effect of water repellents on leaching from CCA treated wood
1995 - IRG/WP 95-50044
CCA treated fence boards brushed with a water repellent finish had consistently lower leaching losses of all CCA components compared to the rate for matched samples without the water repellent. These results are after 12 cycles of simulated rainfall in the laboratory (1800 mm rainfall total) and four months of natural rain exposure in Toronto.
P A Cooper, R MacVicar
Inspection results of preservative treated stakes, maximum 33 years in field
1992 - IRG/WP 92-3690
Since in 1958, we have undertaken field experiments in Japan. For these field experiments, we used sapwoods of Japanese cedar called Sugi (Cryptomeria japonica) because of majority of plantation forest soft wood species in Japan. For some preservatives, we added sapwood of Japanese beech called Buna (Fagus crenata), a main Japanese hard wood species. Dimensions of these specimens were 30 x 30 x 600 mm³ (T x R x L). About 30 preservatives mainly water born but 20% of oil born preservatives included, were examined for this test. We checked the damage rating every year by the observation. The service life of the preservative treated stakes were estimated at the period when the average damage rating of stakes were reached beyond 2.5 . Creosote oil, creosote oil mixed heavy oil (75:25 and 50:50) and creosote oil mixed coal tar (75:25 and 50:50) are still sound conditions for 33 years. CCA (JIS K 1554 Type 1) 2% and Tancas C 2% are still sound conditions for 28 years. Because of soft rot, the treated Buna specimens were shorten as ones of treated Sugi.
K Suzuki, K Yamamoto, M Inoue, S Matsuoka
Cu, Cr and As distribution in soils adjacent to CCA treated utility poles in Eastern Black Sea Region of Turkey
2004 - IRG/WP 04-50214
In this study, the main objective was to asses the distribution of Cu, Cr, and As in soils adjacent to CCA treated utility poles in Eastern Blacksea Region of Turkey (Trabzon, Rize and Artvin ) and determine the influence of soil composition. Surface (0-5cm), subsurface soil samples (30-40cm) were collected near CCA-treated utility poles and control soil samples away from CCA-treated utility poles were also collected. Water holding capacity, pH, mechanical properties of soil samples were determined for both depth levels. Results showed that Cu, Cr and As concentration in soil samples taken from all three cities in 0-5cm depth was higher than soil samples taken from 30-40cm depth. Cu, Cr and As concentrations were much higher in soil samples taken from city of Rize.
E D Gezer, Ü C Yildiz, A Temiz, S Yildiz, E Dizman
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
Leaching of copper, chromium and arsenic from CCA-treated Scots pine exposed in sea water
2000 - IRG/WP 00-50149
A laboratory leaching trial combining a static and a flowing seawater system was carried out to measure the leaching rates of copper, chromium and arsenic from the surface of Scots pine panels vacuum-pressure treated to 3, 6, 12, 24, and 48 kgm-3 CCA. Untreated and treated panels were exposed in flowing seawater for up to 8 weeks followed by 2 weeks submersion in static seawater which was taken for analysis. The study revealed a leaching hierarchy of Cu>Cr>As which supports the findings of other investigators. Over the 8 week leaching trial there was a time-related decrease in the rate of copper and chromium loss. Over the first week of leaching in flowing seawater, the rates of loss of copper and chromium decreased to between one-half and one-seventh, followed by lower rates of leaching over the remaining period of the investigation. In contrast, the rate of loss of arsenic from the wood appeared to increase slightly over the same period. The data are compared with minimal leaching rates of toxins from the surface of anti-fouling paints and are discussed in terms of the fouling communities which are established on Scots pine panels treated to similar target retentions.
C J Brown, R A Eaton
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
Rates of emission from CCA-treated wood in the marine environment: measurement, modelling and requirements for further research
2001 - IRG/WP 01-50166-12
Accurate estimates of rates of emission of leachate from preservative treated wood are crucial for realistic predictions of the environmental impact of its use in maritime construction. Estimates are available for some commonly used preservatives, but these vary widely. Though variable, these measurements suggest that emission generally decreases exponentially with time. Part of the variation is due to differences in methodology employed. Physical and chemical characteristics of the seawater used (e.g. temperature, salinity, pH and oxygen content) affect emission rate. So too do the specifics of the treatment process especially the preservative formulation used, and pre- and post-treatment handling of the wood. The nature of the treated wood samples is also important, with misleadingly high estimates being obtained from samples with unrepresentatively high proportions of cross-cut surfaces. A suggested strategy for developing an informative and standardised methodology is discussed. To form useful models of impacts of leaching, emission rates need to be considered in conjunction with site-specific information regarding a) water exchange rates between the area where leaching occurs and the sea, and b) the extent of partitioning of leachate between the water column, biota and sediment. The risk of environmental impact may be reduced by modification to treatment procedures and by careful planning of installation.
S M Cragg, C J Brown, R A Albuquerque, R A Eaton
Resistance to soft rot of hardwood plywood treated with CCA salt
1983 - IRG/WP 3258
Plywood made from indigenous hardwoods was treated at an average loading of 34 kg Celcure A per m³ and was installed in a field test. After 20 years the samples were only slightly attacked by soft rot and the glue bonds were still intact.
R S Johnstone
Report on the treated piles and fenders in the wharves in Port Moresby harbour, and the Huon Gulf, Lae
1977 - IRG/WP 433
To investigate the resistance of Papua New Guinea timber, vacuum pressure impregnated with Copper-Chrome-Arsenic salts, to marine borer attack in the waters of Papua New Guinea.
S M Rayner, C R Levy
Procedure for a collaborative study of leaching from CCA-treated timber in the sea
1988 - IRG/WP 4143
As a follow-up to the collaborative IRG/COIPM marine trial of CCA and CCB preservatives, a further trial is proposed with the objective of measuring the degree of leaching of CCA components from three timber species at marine sites in Malaysia and the U.K.. Details of the planned procedure are given.
S M Cragg, J E Barnacle, J D Bultman, R A Eaton, B R Johnson, L E Leightley, K D Singh
Soft rot and bacterial decay in preservative treated eucalypt power transmission poles
1982 - IRG/WP 1155
Bacterial type decay was observed in CCA and PCP treated eucalypt power transmission poles. Detailed observations made with the SEM revealed bacterial colonisation and decay, especially in fibres. Plug samples taken from poles throughout Queensland were examined for preservative retention and presence of soft-rot decay. The severity of decay was different according to location, retention and species.
L E Leightley
Above ground performance of CCA-treated fingerjointed lumbe
1993 - IRG/WP 93-40003
Studs made from short lengths by finger jointing are becoming more commonly used in North America. Recently Forintek has received enquiries about the performance of such material in a treated form. Treated and untreated nominal 2x4 inch² spruce-pine-fir (SPF) studs exposed above ground for 12 years in southwestern British Columbia were evaluated for evidence of decay. Despite shallow preservative penetration, which did not meet North American standards, the CCA-treated material showed no signs of decay. In contrast two of the 30 untreated samples had failed and the mean rating was 1.3 on a 0 to 4 scale. These results are encouraging for the use of CCA treated SPF as finger jointed or conventional lumber in above ground exposure.
P I Morris, G E Troughton
Performance results of wood treated with CCA-PEG
1986 - IRG/WP 3363
The addition of polyethylene glycol (PEG) to the CCA system has been shown to reduce the surface hardness of poles and ease spur penetration during climbing. This paper addresses the results of tests dealing with preservative retention and penetration, permanence of CCA and PEG, strength, drying rate, and checking characteristics.
W P Trumble, E E Messina
The Phase Out of CCA in the United States
2002 - IRG/WP 02-50194
In mid-February, 2002 the Administrator of the United States Environmental Protection Agency, Christine Todd Whitman, announced that the US treated wood industry will have until the end of December 2003 to end residential uses for Chromated Copper Arsenate (CCA). Industrial uses of CCA will still be allowed after the December 2003 date. This paper explores the events that led up to the announcement by the US EPA Administrator.
J D Schert