Your search resulted in 250 documents. Displaying 25 entries per page.
L-joint trials: Part 3: Relative performance of a range of preservative products
2002 - IRG/WP 02-30292
Long-term trials using the L-joints described in BS EN 330 and AWPA Standard E9-97 have been in progress at BRE since 1982.
This paper records the current assessments of decay of L-joints in trials started between 1982 and 1994 with treatments applied to both Scots pine sapwood (Pinus sylvestris) and spruce (Picea sp.). Data are provided on a range of active ingredients including TnBTO, PCP, a...
J K Carey
Determination of ethanolamine in impregnated wood
2000 - IRG/WP 00-20198
Leaching of copper based preservatives from wood is usually prevented by adding chromium compounds to copper containing formulations. It seems that suitable substitutes for chromium fixation agents may be amines. In this paper, we report our results on interactions between copper(II) octanoate and ethanolamine (C2H7NO, 2-aminoethanole) with wood or its components. A part of ethanolamine from a woo...
M Humar, M Petric
Copper naphthenate-treated Southern Pine pole stubs in field exposure: - Part 1: Gradient & biodeterioration analysis 12 years after treatment
2000 - IRG/WP 00-30242
Naphthenates have been used for the preservation of timber and cellulose since their original identification in Russia in the early 1880's as part of a series of petroleum characterizations. Later work in the development of copper naphthenate as a heavy-duty preservative for poles led to the development of various treating cycles similar to other oil-borne systems. Recent work concerning ...
H M Barnes, M H Freeman
Effect of boron compounds-furfuryl alcohol treatment of wood on dimensional stability, termite resistance and boron leachability
2001 - IRG/WP 01-40195
Sapwood blocks of Japanese cedar (Cryptomeria japonica) and Caribbean pitch pine (Pinus caribaea) measuring 20 (tangential) x 20 (radial) x 10 (longitudinal) mm were impregnated with furfuryl alcohol (FFA) by a vacuum-diffusion process followed by curing under heating. Boron compounds (boric acid, ammonium borate and ammonium biborate) were mixed in the impregnation solution of FFA. Anti- swelling...
S K Ozaki, M K Yalinkilic, Y Imamura, M F Souza
X-ray photoelectron spectroscopic analysis of CCA treated wood
1992 - IRG/WP 92-3700
Ponderosa pine and Douglas-fir wood sections were treated with CCA preservative. To elucidate the mechanism of fixation of the CCA, the wood surface was analyzed by X-ray photoelectron spectroscopy (XPS). CCA treatment increased C1 (carbon bonded to carbon and/or hydrogen) and decreased C2 (carbon bonded to one oxygen) in XPS C1s spectra, both in unextracted and pre-extracted sections. This sugges...
J N R Ruddick, K Yamamoto, P C Wong, K A R Mitchell
Multiple-Phase Pressure (MPP) Process: Pilot plant trials for disposal of kickback using reverse osmosis membrane filtration
2001 - IRG/WP 01-40202
The MPP Process (a one-stage CCA treatment and accelerated fixation process) generates ~ 250 litres of kickback per cubic metre of timber treated. Composition of kickback is mainly wood sugars and traces of copper, chromium and arsenic. In pilot plant scale trials, MPP process kickback was filtered through a Reverse Osmosis (RO) membrane of a type found from earlier small-scale trials to be the mo...
H Pearson, G Durbin, M E Hedley
L-joint trials: Part 1: Observations on the process of colonisation and decay
2002 - IRG/WP 02-20250
The first trials using the small L-joint, later adopted for use in BS EN 330 and AWPA Standard E9-97 were exposed at BRE in 1975 but all were assessed destructively during the early stages of exposure. The longest running trial which included replicates for long-term exposure will have been exposed for 20 years in July 2002. This paper provides an overview of the results of testing during that p...
J K Carey
Variation in natural durability of British grown Douglas fir ((Pseudotsuga menziesii (Mirb.) Franco). Part I. Effect of density and growth rate
2002 - IRG/WP 02-10445
Seed origin trials of Douglas fir (Pseudotsuga menziesii) in Britain have provided important information on growth differences between origins (Lines, 1987), but the variation in wood properties between origins has not been reported. The present paper describes a study of the variation in natural durability against two brown rot fungi (Coniophora puteana and Postia (Poria) placenta) and in a fung...
S Akhter, M D C Hale
Applications of the shower test. Part A: Results from CCA type C treated wood: influence of fixation process
1993 - IRG/WP 93-50009
This report outlines the results of shower tests conducted on CCA type C treated wood. The results indicate the inherent good fixation of CCA type C, as judged by the leaching limits within the Environmental Regulations. The shower test has proven to be a useful quality control and research test. It determines reasonably accurately the leaching under simulated conditions and, admittedly from a lim...
W J Homan, H Militz, D A Lewis
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 5: Effect of wood species and preservative composition on the leaching during storage
1975 - IRG/WP 354
Conversion reactions during storage of CCA treated wood take place even at and below the fiber saturation point as long as ion transport is possible. Increase in drying temperature increases the final pH of the treated wood and the leachability of Cu and decreases slightly the leachability of Cr, while the leachability of As is not affected. This temperature effect is considered to be of no techni...
S-E Dahlgren
Incomplete fixation of chromium in the pre-treated wood with a solution of copper and arsenic compounds
1995 - IRG/WP 95-50052
Ponderosa pine wood thin sections were treated with a combination of chromium, copper, and arsenic chemicals. The wood sections was analyzed by electron spin resonance spectrometry (ESR) and X-ray photoelectron spectrometry (XPS) to elucidate the mechanism of fixation of the chromated-copper preservatives. The wood subjected to the two-step treatment with copper and arsenic followed by chromium ex...
J N R Ruddick, K Yamamoto, F G Herring, P C Wong, K A R Mitchell
Tests with ammoniacal copper and alkyl ammonium compounds as wood preservatives
1984 - IRG/WP 3299
Formulations based on copper and alkyl ammonium compounds in ammonia solution have been tested in a fungus cellar on Pinus radiata and Fagus sylvatica. This type of products gives promising results as wood preservatives, especially on hardwood and are safe to destroy by e.g. combustion. The best results were achieved with a dialkyl ammonium compound, Cu/octyldecyl dimethyl ammonium chloride (NH3)....
C-E Sundman
Soluble nutrient influences on toxicity and permanence of CCA preservatives in wood
1980 - IRG/WP 3144
The influence of soluble carbohydrate and nitrogenous components concentrated at evaporative surfaces of wood on the toxicity and permanence of CCA preservatives has been examined using soil-burial techniques. Nutrient concentrations in lime (Tilia vulgaris Hayne) have been shown to be associated with reduction of toxic limits of preservatives to an extent in which a 100% increase in preservative ...
B King, G M Smith, A Bruce
Comparison of methods for monitoring CCA fixation
1994 - IRG/WP 94-40023
The CCA fixation status in the outer 12.5 mm of pole sections of southern pine (Pinus sp.), red pine (Pinus resinosa) and lodgepole pine (Pinus contorta var. latifolia) were followed during fixation at 21°C under non-drying conditions by the following procedures: - Qualitative CrVI indication by the chromotropic acid spot test. - Quantitative CrVI in the expressate by the diphenylcarbazide method...
P A Cooper, Y T Ung, G Zanjani
A laboratory study on effect of coating materials on leaching of copper from CCA treated wood
2001 - IRG/WP 01-50176
Components of CCA preservatives can leach into surrounding soil and water and have some effect on germination and growth of some plants. In this report, the effect of coating materials in reducing chemical concentration in the leachate were evaluated. Rubber wood blocks (Hevea brasiliensis) treated with CCA were fixed at room temperature at high humidity. After air dried, they were painted with co...
A Veenin, T Veenin
Rainfall simulation to assess CCA permanence
1991 - IRG/WP 2373
During experimental work on accelerated fixation of chromium containing preservatives a method has been developed which compares the degree of preservative levels of contamination of simulated preservative fixation in timber with the levels of simulated rainfall. This method uses commercial sized wood sections wetted in a way that simulates actual rainfall and relates the associated run-off contam...
P Warburton, J A Cornfield
The effect of composition on the effectiveness and fixation of CCA and copper/chrome preservatives. Part 1: Effectiveness. Part 2: Selective absorption and fixation
1973 - IRG/WP 324
A preliminary study of a wide range of copper-chrome-arsenic formulations indicates that the most effective are in the region, CuSO4 · 5H2O - 35 to 45 per cent; K2Cr2O7 - 40 per cent and above; As2O5 · 2H2O - 25 to 15 per cent or less. Effectiveness appears to depend more on the copper content than the copper - arsenic. Observations on selective absorption and leaching suggest that the chromium ...
D N R Smith, A I Williams
The relationship between the electrical resistance and fixation of water-borne CCA salts and pressure-treated wood
1991 - IRG/WP 3657
Two investigations at 22°C and 30°C have been carried out. The electrical resistance in the treated wood and chemical analyses of the remaining amount of unfixed copper, chromium and arsenic were investigated. Samples impregnated with water were used as references. To hold the samples moist during the investigation, each sample was wrapped in a polyethylene plastic foil immediately after impregn...
F G Evans, B Nossen
Respiration measurement of dry-rot
1995 - IRG/WP 95-10095
Methods for measuring the production of carbondioxide from wood infected with the dry-rot fungus were evaluated. By enclosing whole wood blocks and measuring the concentration of gas in the headspace by gas chromatography, an exponential increase in the concentration of CO2 was observed for at least 2 months. This technique could therefore present a method for evaluating various treatments of dry-...
L Toft
Leachability of didecyldimethylammonium chloride (a quaternary ammonium compound) from four wood species
1982 - IRG/WP 3204
Sapwood blocks prepared from red pine, ponderosa pine, southern yellow pine and hem-fir (a commercial mixture of western hemlock and amabilis fir) were treated with didecyldimethylammonium chloride, (an alkylammonium compound, AAC). After oven drying the blocks were vacuum impregnated with distilled water and subjected to a static leach cycle for 48 hours. The leachate was analyzed and the amount ...
J N R Ruddick, A R H Sam
Effect of water repellents on leaching of CCA from treated fence and deck units - An update
1997 - IRG/WP 97-50086
In an earlier study, it was shown that CCA leaching losses could be reduced over an accelerated leaching and short term natural weathering exposures by post treatment application of a commercial water repellent. In this report, the effects of this coating and two commercial CCA solution water repellent additives are evaluated after two years of natural weathering. Wood boards were pressure treated...
P A Cooper, Y T Ung, R M Vicar
Susceptibility of CCA treated North American hardwoods to Chaetomium globosum decay
1998 - IRG/WP 98-10278
Seven species of hardwood, Beech (Fagus grandifolia), Basswood (Tilia americana), Maple (Acer rubrum), Oak (Quercus rubra), Trembling Aspen (Populus tremuloides), White birch (Betula papyrifera) and Yellow poplar (Liriodendron tulipifera) were vacuum or pressure impregnated with CCA, at four retention levels. The CCA was allowed to fix in the wood at 35°C. Red pine (Pinus resinosa) was also inclu...
U Srinivasan, Y T Ung, P A Cooper
Waterborne preservative treatability of tamarack (Larix laricina (Du Roi) K.Koch)
1998 - IRG/WP 98-40112
Eastern larch or tamarack (Larix laricina (Du Roi) K.Koch) lumber from New Brunswick, Canada was evaluated for preservative treatability with chromated copper arsenate (CCA-C) and ammoniacal copper arsenate (ACA). The fixation and leaching characteristics of CCA-C treated tamarack sapwood and heartwood were also evaluated. CCA-C penetration into both sapwood and heartwood was poor. ACA fully penet...
A Taylor, Y T Ung, P A Cooper
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 c...
S-E Dahlgren
Chromium in wood preservation: Health and environmental aspects
1978 - IRG/WP 3120
The majority of water-borne salts in current use contain hexavalent chromium, usually as dichromate or chromium trioxide. In about 1913 it was suggested that chromates, phosphates or borates could be added to the sodium fluoride and dinitrophenol mixtures then in use in order to inhibit corrosion. Dichromates were found to be most suitable and the resulting mixture known as Thriolith and later Tri...
T R G Cox, B A Richardson