Your search resulted in 338 documents. Displaying 25 entries per page.
Standardization of CCA treated 45 hardwood species grown in Bangladesh for REB crossarms
1995 - IRG/WP 95-20059
Researches on 45 hardwood species grown in Bangladesh regarding density, moduli of rupture (MOR), colour and treatability of sapwood and heartwood, seasoning property and natural durability of heartwood revealed that both sapwood and heartwood of 17 species could be full cell pressure treated with CCA at impregnation pressure of 14-18 kg/cm² and only sapwood of rest 28 species could be pressure treated. Hartwood of 28 species were found to be mostly refractory to treatment but naturally fairly durable to very durable when used indoor or overhead exposed conditions. The MOR of 45 timber species varied from 58-96 N/mm² at green conditions, sufficiently strong for distribution crossarms. The most dense timbers were found to be kilndried slowly and effectively. Inherent strength, conventional sawing, conventional grading with pilodyn, kilndrying before treatment and slow air-drying before outdoor storing upto EMC (19% MC) at centerline of crossarms and adequate CCA-C treatment in treatable areas would ensure long term utilization of these timbers in Rural Electric Systems in Bangladesh.
A K Lahiry
Moisture content levels and decay of hemlock
1986 - IRG/WP 1287
As a model of decay conditions of wooden members in wooden houses, a decay test was set up in which samples of western hemlock (Tsuga heterophylla) under 4 moisture levels were examined. Each week the samples were weighed and if the weights indicated that their moisture contents were lower than the expected levels, distilled water was added. Every 8 weeks 3 samples from each condition were oven dried at 60°C for 48 hours, up to 48 weeks. After 48 weeks, 3 samples from each condition were oven dried every 16 weeks. The results obtained were as follows: After examining the samples for 96 weeks at 27°C, the mean weight loss of the hemlock samples kept at about 50-100% moisture content level was larger than those of the other levels. If the samples were dried every 8 weeks, the amount of decay in them was not significant. Decay was also not significant in the samples kept at approximately 20-30% moisture content level.
New technique to analyze impregnation processes
1988 - IRG/WP 2304
Equipment has been developed to measure liquid flow in wood during impregnation processes. Basic principles of flow measurements using directly heated negative temperature coefficient thermistors, and some characteristics of the hardware developed are presented in this paper.
J P Hösli
Influence of moisture content of rubber wood on the growth of Botryodiplodia theobromae
1993 - IRG/WP 93-10029
Botryodiplodia theobromae is the main fungus causing sapstain on rubber wood (Hevea brasiliensis). The entry and establishment of the stain fungus is nighly influenced by the moisture content of the wood. To determine the optimum moisture content of wood required for maximum growth of Botryodiplodia theobromae wood blocks at different moisture contents were inoculated with the test fungus and incubated for a period of two weeks. The study showed if the moisture content of the wood was reduced to less than 24%, the wood can be protected from fungal sapstain.
E J M Florence, R Gnanaharan, J K Sharma
Soil virulence tests using Scots pine sapwood
1973 - IRG/WP 222
Following the tests reported in Document No: IRG/WP/210, in which soils from different laboratories were investigated for virulence, supplementary tests have been carried out using Scots pine sapwood and an extended incubation period.
J K Carey, J G Savory
Co-operative research project on L-joint testing. Sampling after 8 months exposure
1983 - IRG/WP 2208
It was anticipated in Document No IRG/WP/2192 that exposure of L-joints by the European co-operators would take place on 1 April 1983. Where L-joints were exposed at this time, sampling after 8 months exposure is due on 1 December 1983. The present document draws attention to relevant previous documents which describe the sampling methods to be adopted. It also provides Tables for recording the results.
J K Carey, A F Bravery
Comparison of the agar-block and soil-block methods used for evaluation of fungitoxic value of QAC and CCA wood preservatives
1994 - IRG/WP 94-20039
The modyfied agar-block and soil-block methods were used for comparing the fungitoxic value of QAC and CCA type preservatives against Coniophora puteana and Coniophora olivacea The mass loss and moisture contents of wood were analysed.
J Wazny, L J Cookson
Collaborative soft rot tests: Programme and test method
1973 - IRG/WP 229
J G Savory, J K Carey
Collaborative soft rot tests: Interim report on PRL tests of Cu/Cr/As preservative using method of Document No: IRG/WP/208
1972 - IRG/WP 211
Preservative: Tanalith CT.106 - Results obtained with beech are given in the table and indicate a toxic limit of 16.7-19.2 kg/m³ - The initial soil moisture content was adjusted to 27.8% (the water holding capacity). Noticeable drying out has occurred in some of the test bottles.
J G Savory
Observations on the failure of anti-sapstain treated timber under non-drying conditions
1990 - IRG/WP 1437
A range of bacteria and yeasts were isolated from antisapstain treated timber and fresh sawdust. Solution samples containing 100 ppm of TCMTB in a nutrient medium were inoculated with these organisms and incubated at 25°C for 5 days. The levels of TCMTB remaining in solution were determined by HPLC analysis after this time. Results indicated high losses of active ingredient for a range of organisms. These results suggest that active biodetoxification of organic biocides could occur in a short period of time during storage of antisapstain treated timber under favourable conditions. The implications of these results are discussed.
G R Williams
A standardised procedure for the treatment of timber with test chemicals
1986 - IRG/WP 2257
A procedure is described which allows the standardisation of sample handling and data manipulation during trials invastigating the treatability of timber with test chemicals. The use of computer software allows the data to be handled efficiently.
J Norton, A Zosars, L E Leightley
Co-operative research project on L-joint testing. Progress report to March 1988
1988 - IRG/WP 2315
Further sets of data received from CTFT (France), BAM (Germany) and PRL (UK) after 46-48 months exposure and STU (Sweden) after 22 months exposure are presented and discussed in conjunction with data reported previously. Colonisation and attack of the L-joints has progressed with increasing exposure period. The new data are generally in agreement with those presented previously and the major difference between Institutes continues to be one of rate of colonisation rather than any relative difference in performance of the treatments. Overall 0.5% TnBTO 1 min dip treatment is providing least protection followed by 1.0% TnBTO 1 min dip treatment. The double vacuum treatments continue to provide better protection than the dip treatments; there are now indications that 0.5% TnBTO double vacuum treatment is less effective than 1.0% TnBTO.
J K Carey, A F Bravery
Diffusion of fused borate rods in top ends of poles
1989 - IRG/WP 3518
Diffusion tests of fused borate rods were carried out on extremities of sapwood poles in service. Rods were set in drills under the cone with or without addition of liquid Boracol 40. After one year of weathering, a good diffusion in the slice under the cone and even below the slice and in the cone itself was observed in Scots pine and spruce poles. The rods were still intacts and constitute, in fact, a reserve of boric acid for the future. This type of treatment would be satisfactory as secondary treatments of poles in service.
D Dirol, J P Guder
Analysing the characteristic role of moisture content for drying and fluid flow in Sitka spruce. - Part 1: The drying process of sapwood and heartwood of two different thickness of Sitka spruce using a kiln. - Part 2: Effects of moisture content on longitudinal permeability of Sitka spruce in vertical variation of the tree
2000 - IRG/WP 00-40173
The characteristic role of the moisture content in Sitka spruce (Picea sitchensis (Bong.) Carr.) that grown in the United Kingdom was examined by this study on the basis of (1) the reduction of moisture content in two different thickness of sapwood and heartwood by kiln drying process, and (2) the effects of moisture content to the longitudinal void volume filled of tanalith-C by the full-cell process from base (1 m) to apex (3 m) of the tree in sapwood zone. Accordingly, conclusions on indication of the drying process of sapwood and heartwood, and vertical variation of longitudinal flow with effects of moisture were listed separately: (1) Comparison of Drying Characteristic of Sapwood and Heartwood: The two different thickness (300x30x30 mm3 and 300x20x20 mm3) of sapwood and heartwood of Sitka spruce was dried using the suggested drying schedule in kiln. The reduction of moisture was schematically diagrammed according to sapwood and heartwood stakes. The reduction of moisture followed the same downward trend that sapwood (S) loses more moisture than heartwood (H) although the small stakes of S and H lost moisture rapidly compared with the large ones. (2) Vertical Variation of Moisture Content and Longitudinal Permeability: The 90 kiln dried defect free sapwood stakes (150x25x25 mm3) of Sitka spruce was taken from base to apex of the trees at 1, 2 and 3 m above ground level. After having the determination of moisture content in each experimental stake, the treatment was carried out by the full-cell process with CCA preservative (Tanalith-C) using a model pressure treatment plant. Significant differences observed among the tree heights from 1 to 3 m showing that slightly increases of moisture content from base to apex and conversely decreases of longitudinal void volume filled by preservative fluid.
Effects of pretreatments for the amelioration of preservative impregnability using the Oscillating pressure method (OPM)
1995 - IRG/WP 95-40044
For the purpose of an amelioration of preservative impregnability, three types of pretreatment: the steaming, the explosion and the boiling, were tested. The specimens were prepared by the domestic four species: Itajii, Ryukyumatsu, Sugi and Hinoki, and 1 refractry imported species: Douglas-fir. The dimension of specimens was 20 x 20 x 300 mm³ and were treated with CCA in a laboratory OPM machine. Three OPM schedules and Bethel process without after vacuume were tested in this experiment. The results obtained were follows: 1. In the case of the treatment of green woods, the calculated retentions of preservatives based on those initial mass, were periodically slowly increased or sometimes decreased. This reason was considered the replacement of the free water in wood to the preservative solution. The sapwood of rather easy treatable species like Ryukyumatsu, was obtained good penetration by Bethel process. The sapwoods of treatable species like Sugi and Hinoki, were obtained best penetration by OPM-1 or by OPM-2. The combination of the steaming and the OPM was rather good results for all species tested of green woods. 2. In the case of the treatment of the air-dried woods, the combination of the steaming and the OPM was obtained rather good results for all species tested included the refractry specimens like Douglas-fir.
K Suzuki, I Asaoka, S Tani, K Okada, T Hidaka
Specific gravity and moisture content of particleboards treated with various chemicals
2005 - IRG/WP 05-40310
The aim of the study was to investigated the effects of particleboard treated with various chemical substances on specific gravity and moisture content The wood raw material used in the experiments were the mixture of coniferous wood [70%, Pinus brutia Ten., Pinus nigra Arn (Lamb.), Cedrus libani Ait.] and black poplar (30%, Populus nigra L.). In this mixture, barks have been accepted up to 5 percent. The used chemicals were in the concentrations of 10-8 % urea-formaldehyde, 10 % ammonium clorure, 10 % rosin, 20 % alkyd resin, 5 % boric acid, 7 % ammonium sulfate, 10 % tanalith-CBC, 5 % borax, 1.76 % immersol-WR 2000, 2.5 / 2.5 % boric acid/borax, 5 / 2.5 / 2.5 % tanalith-CBC/boric acid/borax. According to the result of this study; for all of the particleboards, the density and the moisture content increased with increasing the chemical agents ratio used.
Ü C Yildiz, A A Var, H Kalaycioglu, S Yildiz
The variation in electrical resistance in the CCA-treated wood during the fixation
1989 - IRG/WP 3554
The curve commonly used in Scandinavia for describing the fixation period at different temperatures for CCA-impregnated wood is based on investigation by Dahlgren on the pH-variations in a mixture of sawdust and preservative solution. As far as we know there is no such investigation on solid wood. We have therefore measured the electrical resistance in CCA-treated solid wood to see if this will differ according to the different ion consentrations that are in the wood during the fixation process. Our investigation shows that the electrical resistance in the CCA-treated wood varies. At first the resistance will increase, then it will decrease and at last stabilize at a higher ohm-value than in the start. This variation may describe the fixation in the wood and perhaps be used to measure the fixation time at different temperatures for solid, impregnated wood.
F G Evans, B Nossen
A new approach to the maintenance of wooden railway sleepers. (Second report)
1988 - IRG/WP 3492
The microenvironment and micro-ecology of wooden railway sleepers was investigated to assess their condition to determine the necessary treatment, repair and replacement criteria. In this report the efficacy of the secondary preservative treatment with solid boron rods is discussed and the development of an in-situ, nondestructive test method based on the creation and assessment of structural dynamic vibrations is described.
W Beauford, P I Morris, A M Brown, D J Dickinson
The effect of service life and preservative treatment on the hardness of wooden poles
1989 - IRG/WP 3537
The surface hardness of utility poles is an important parameter which effects the acceptability of the pole as being safe to climb during line maintenance. The current investigation was designed to evaluate how the surface hardness of preservative treated utility poles is effected by the type of preservative, and the age of the poles. Chromated-copper-arsenate (CCA) treated red pine and jack pine poles which had been in place for up to forty years were located in Bell Canada's system in Ontario, and screened for use in the project. A survey of poles in three locations was made, and data collected on surface hardness using a 6-Joule Pilodyn. Other information recorded included the wood species identified by the brand, and the moisture content (using a resistance type moisture meter). Core samples were removed from each pole for subsequent measurement of preservative retention. The CCA retentions were determined using an X-ray analysis.
E B Jonsson, E M A Nilsson, J N R Ruddick
Emission of trimethyl borate and methanol from radiata pine (Pinus radiata D. Don)
1995 - IRG/WP 95-30088
Sawn and kiln dried radiata pine conditioned to 3, 6, and 12% moisture content was treated with trimethyl borate (TMB). The treated wood samples were placed in mini-desiccators maintained at 20 or 40°C. The air space within the mini-desiccator was analysed for TMB and methanol. An initial period of emission of TMB and methanol was observed. This was followed by a period of gradual dissipation of both TMB and alcohol. There was an equilibrium of 2 ppm and 60 ppm respectively of TMB and methanol for 12% moisture content timber stored at 20°C. Dissipation was slower for 6% and 3% moisture content timber. Higher temperatures resulted in higher concentrations of TMB and methanol during the emission and dissipation stage.
F J Romero, P Vinden, J A Drysdale
Some observations on miniaturised soil/block tests
1988 - IRG/WP 2317
Results are presented for miniaturised soil/block tests carried out in 120 ml capacity glass jars. The four test fungi (Coniophora puteana, Coriolus versicolor, Gloeophyllum trabeum and Poria placenta) reacted differently to different moisture regimes established by varying the soil moisture content. Acceptable levels of decay were achieved by the three brown rot fungi with soil at 110% whc; however, soil at 150% whc failed to provide a high enough moisture content in the test blocks for decay by the white rot Coriolus versicolor. Overlaying test blocks exposed to Coriolus versicolor with moist sterile vermiculite increased both moisture contents and decay.
J K Carey
Report on questionnaire: Facility for accelerated stake tests in unsterile soil
1983 - IRG/WP 2169
In October 1981 a questionnaire (IRG Doc. No. IRG/WP/2166) on the so-called fungus cellar tests in unsterile soil was prepared and despatched to 56 individuals representing various institutes, organisations, or companies. In addition a further 68 letters describing the purpose of the questionnaire were sent to additional IRG members who could request the full questionnaire if appropriate. This represented a contact with 125 individuals in 48 countries. A verbal report on the results of this survey was presented at IRG 13 in Cesme, Turkey. The present document formalises that report.
J A Butcher
Development of a method for testing wood preservatives with soft rot fungi
1975 - IRG/WP 250
Although the first publications on experimental soft rot attack date back 20 years ago, so far no test method for evaluating the efficacy of wood preservatives against soft rot attack (Ascomycetes and Fungi Imperfecti) has been generally accepted. The reasons are diverse and the shortcomings and the disadvantages of the methods described are well known and have repeatedly been discussed. The soil burial method developed by G. THEDEN (1961) using non-sterilised soils with their natural flora of micro-organisms is said to be poorly reproducible. One possibility to work with clearly defined test fungi and easily reproducible test conditions was developed and described by P. KAUNE in the BAM as the vermiculite burial method. For the further development of this method, in the past years numerous investigations have been made in the BAM to select test fungi and define a test arrangement. Their results will be summarised below.
M Gersonde, W Kerner-Gang
Collaborative soft rot test: Amended test method
1972 - IRG/WP 208
The initial draft of a standard test method (Document IRG/WP/201) was discussed at the meeting in Brussels in 1971. It was agreed that a revised draft should be prepared and that the Princes Risborough Laboratory (formerly FPRL) should conduct a trial test using the method as a preliminary to the main collaborative test.
J G Savory
A summary of tests and practical experiences with the Pilodyn wood testing instrument
1980 - IRG/WP 282
This paper presents a summary of the reports, tests and practical experiences with the Pilodyn wood tester not only, however, concerning poles but also in other fields such as standing trees, sawn timber etc. The principle of the Pilodyn is a spring-loaded pin which is fired into the object and the depth to which the pin penetrates is correlated to physical and mechanical properties of the object.