Your search resulted in 149 documents. Displaying 25 entries per page.
Laboratory tests on natural resistance to Cryptotermes brevis (Walker) attack of native hardwoods for crossarms production
1985 - IRG/WP 1266
Eletropaulo (Eletricidade de Sao Paulo S/A) and IPT (Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo S/A) are carrying on a study to evaluate wood species for crossarms in replacement of Aspidosperma polyneuron - Apocynaceae (Peroba-rosa) traditionally used for this purpose. Nineteen Amazon wood species were elected, with physical and mechanical properties equal or better than those presented by Peroba-rosa. Biological tests with these woods and physical tests of crossarms were carried out. Here is presented the results of the resistance test to Cryptotermes brevis attack.
M D Canedo, A T De Lelis
The susceptibility of 35 Amazon wood species to Cryptotermes brevis (Walker)
1982 - IRG/WP 1160
Laboratory tests were carried to evaluate the susceptibility of 35 Amazon hardwoods to Cryptotermes brevis (Walker). The results were analysed statistically and showed that five wood species were non resistant, nine were resistant and the other twenty-one in between those classes of resistance.
M D Canedo
Chemical treatment of ten Amazonian timber species of low natural durability
1991 - IRG/WP 3640
The objective of this work was to evaluate the performance of 10 amazonian wood species of low natural durability, to treatment with CCA preservative (2% concentration): it was concluded that all species studied are easily treated with this preservative. The sapwood showed high absorption and total penetration. The heartwood is relatively easy to preserve, exception to Parkia nitidae (Fava), Qualea paraensis (Mandioqueiras), Erisma unicatum (Quarubarana), and Virola sp (Ucuúba), which presented some restrictions. Nevertheless, it does not mean that their treatment is impossible.
C S Neta, B F Vianez
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.
Performance of preservative-treated hardwoods with particular reference to soft rot. Report of condition of specimens installed in Victoria, Australia
1980 - IRG/WP 3155
J Beesley, R McCarthy
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
Coding scheme for samples for IRG world-wide co-operative field experiment
1975 - IRG/WP 360
Each sample has been given a number containing six digits (eg 16 23 05). The first 2 digits indicate the country and person supplying the timber, the second 2 digits indicate the species of timber, and the last two digits indicate the treating concentration. All samples which end with the numbers 26 to 50 are to be placed in one site in the United Kingdom, probably at the Imperial College site at Silwood. All the other samples will be returned to the persons in the following list according to the code number indicated.
Progress towards controlling soft rot of treated hardwood poles in Australia
1977 - IRG/WP 289
CCA modifications and their effect on soft rot in hardwoods
1982 - IRG/WP 3201
Decay tests were carried out on wood samples treated with three waterborne compounds all identical in composition but applied in different forms. There were significant differences in the effectiveness of the treatments particularly as regards the control of soft rot.
S M Gray, D J Dickinson
Field tests out of ground contact in France: Definition of the test procedure and preliminary results after 18 months
1981 - IRG/WP 2161
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
Letter to the IRG meeting at Peebles, 1978
1978 - IRG/WP 181
J F Levy, R Cockcroft
Improved PEC preservatives with added biocides
1985 - IRG/WP 3322
Biocidal chemicals have been incorporated into formulations within the broad framework of pigment emulsified creosote (PEC) to provide novel potential multi-purpose preservatives. Preparations of PEC plus TCMTB, Boracol 40, copper ethanolamine nonanoate, Quatramine 80, arsenic trioxide, Troysan Polyphase, and CCA have been formulated and assessed for preserving ability in soil-jar and Accelerated Field Simulator tests. In addition, a cationic oil-in-water emulsion preservative combination of PEC and CCA (PECCA), and an anionic formulation of TCMTB with PEC (PECBUS) have been manufactured in 400 L quantities to treat hardwood pole stubs and pine posts. The results indicate the potential of these improved second generation PEC-based preservatives to provide low-creosote containing treatments able to protect commodities against biodeterioration as well as provide dry, clean surfaces.
H Greaves, C-W Chin, J B Watkins
Performance of surface-treated hardwoods and softwoods out of ground contact
1990 - IRG/WP 3592
A number of fungicides were tested as brush treatments for protection of southern pine, Douglas-fir, maple, and red oak against decay above ground. Cross-brace and L-joint test units were treated just before assembly and exposed from 3-10 years. Untreated Douglas-fir cross-brace units were not decayed at either the Mississippi or Madison, WI, site. Untreated red oak cross-brace units were not decayed at the Madison site. The two hardwood species were more difficult to protect from decay than the softwood species. Decay development in maple cross-brace units was considerably slowed by several of the treatments but none of the treatments provided complete protection from decay during the 9 or 10 years exposure in Mississippi. Most of the treatments did not reduce decay development in red oak cross-brace units. Many treatments protected pine cross-brace units. The L-joints were exposed for only 3-4 years, but appear more difficult to protect from decay than the cross-brace units.
T L Highley
Recent soft-rot research in softwoods and hardwoods
1980 - IRG/WP 1108
The purpose of this paper is to describe briefly the current status of our research on soft-rot fungi. The work to be discussed is still in progress and any results described must be regarded as provisional.
J A Butcher
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
The interaction of polyflavonoid tannins with CCA in Pinus radiata
1987 - IRG/WP 3422
Polyflavonoid tannins complex easily and rapidly with metal ions such as copper, chromium, and arsenic. such complexes in high-tannin-containing CCA treated hardwoods might result in essentially under-treated timber. Four aspects of this interaction were investigated: 1) The relationship between tannin contents of seven hardwoods (Betula pendula, Alstonia scholaris, Fagus sylvatica, Liquidambar styraciflua, Nothofagus menziesii, Platanus acerifolia and Tilia vulgaris) and one softwood (Pinus radiata) and% Cu toxic thresholds; 2) Determination of tannin distribution within cell wall layers; 3) The field performance of Pinus radiata treated with solutions of bark tannin, then CCA; 4) TEM/EDAX studies on CCA loadings in the S2 layer of tannin/CCA treated Pinus radiata tracheids. Our observations suggest that by themselves tannins have a minor influence on field performance of CCA-treated hardwoods.
K G Ryan, D V Plackett
Wood in concrete. Summary of discussion at IRG 14, Surfers Paradise, Australia
1984 - IRG/WP 3264
The performance of untreated and preservative treated wood when placed in direct contact with concrete was considered in a discussion session at IRG 14. While published reports in this area are scarce, research is in progress internationally and a variety of practices are currently available to minimize any additional hazard posed by contact with concrete. This report summarizes the points raised at the IRG discussion.
R J Murphy
Natural resistance of twenty-six Guianese wood species against marine borers
1988 - IRG/WP 4144
This note is a contribution on the study of the natural resistance of some wood species from French Guiana, some of which could be found too in the neighbourhood. Here are presented the results after one year exposure in the marine environment.
L N Trong
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water: Final report
1987 - IRG/WP 4133
Three timbers chosen as reference species were treated with 3, 6 and 10% solutions of CCA and CCB preservatives and exposed for up to 93 months at 8 tropical and temperate marine sites. Eleven local species treated in the same way were exposed at 4 of the 8 sites. There was no apparent difference in performance between CCA and CCB treated specimens. The severest test site was Panama Canal but marine borer damage of specimens was recorded at all the test sites. Treated specimens of the reference species Alstonia scholaris and Pinus sylvestris were markedly superior in performance at all sites and Homalium foetidum was considered the best local species. Along with the reference species Fagus sylvatica, treated specimens of the remaining local species performed relatively poorly. All treated species were attacked by soft rot fungi, except treated Alstonia scholaris and Homalium foetidum which were superficially decayed by bacteria. The relative success of treated Alstonia scholaris in this trial is attributed to its permeability characteristics and acceptance of high preservative loadings, even preservative distribution and its high lignin content.
R A Eaton
The biological natural durability of timber in ground contact
1994 - IRG/WP 94-20051
The BRE ground contact field trials for the determination of the biological natural durability of different timber species have recently been reviewed. The data obtained from these trials have been used to appraise the different ways in which natural durability may be expressed. It is concluded that the use of the mean as a method of assigning the timber to one of five durability classes may be acceptable where general recommendations are required, for instance in association with the use of wood preservatives to enhance durability, but that the median provides a better indication in this context. Where a specifier requires more detailed information on timber performance, the mean (or median) is inappropriate and a system of percentile values would be more informative.
G A Smith, R J Orsler
Technique for monitoring absorption during a vacuum pressure process
1992 - IRG/WP 92-3696
A laboratory technique was developed and an apparatus constructed which allowed for the direct and continuous measurement and observation of volumetric uptake of water-borne preservative into wood samples throughout a controlled vacuum-pressure treatment process. Fractional filling of void space was calculated. Graphing (fractional saturation) against time allows prediction of optimum cycle lengths with respect to achievable saturation values. Treatability evaluations using this technique were carried out on heartwood samples of six Malaysian hardwood species, kapur, kempas, keruing, punah, rubberwood, simpoh and on sapwood samples of Scots pine as a control. Generally the graphs exhibited two quasi-linear zones showing rapid initial absorption followed by slow absorption over a long period.
A J Pendlebury, J A Petty
Treatment of messmate (Eucalyptus obliqua L'Hérit) by double-diffusion: Preliminary report
1983 - IRG/WP 3234
Modified double-diffusion is suggested as a method of impregnation for mixed tropical hardwoods for certain types of ground contact use in less developed countries. Compared with vacuum/pressure impregnation, capital costs are low and little skill is needed for the operations involved. Treatment of messmate (Eucalyptus obliqua L'Herit) rounds involving pre-heating in water prior to their immersion in the first stage solutions is described. Preliminary indications are that (i) there is a deeper penetration of arsenic when a compound of this element is used in the first stage solution (ii) a more even and deeper penetration of chromium is obtained when sodium chromate, rather than sodium dichromate, is used in the second stage solution. It is concluded that quality control in double-diffusion may be a limiting factor in the adoption of the process for the treatment of wood unless a simple but effective method is found to control solution concentrations and elemental ratios.
F F K Ampong, C-W Chin