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Effectiveness of "Gang-Nail" plates in preventing splitting of Eucalyptus poles and Brazilian hardwood sleepers
1984 - IRG/WP 3262
This paper presents the results of some tests carried out with an anti-splitting device, placed on the end surfaces of Eucalyptus spp utility poles and Brazilian hardwood sleepers at the beginning of an air-drying period. The type of device used, a "Gang-Nail" plate, reduces significantly the splits at the end-surface of poles, but reduces only a little the splits occurring in sleepers.
A M F Oliveira, J A C Sodré, O B Neto


A comparative study of some anti-splitting devices, using Eucalyptus saligna and hybrids of Eucalyptus saligna X Eucalyptus spp poles
1983 - IRG/WP 3251
It is commom for some Brazilian wood pole users to require devices such as banding steel, to avoid or reduce splits at the end of Eucalyptus treated poles. On other hand users and manufacturers do not have data to confirm the effectiveness of the banding steel types normally used such as galvanized "Steel-Belt" and galvanized "Wire-Belt". For this reason a comparative study was carried out including in addition to the above, "Steel-Plates" (Gang-Nail type) and the "Kerfing" procedure. These devices were tried out on Eucalyptus saligna hybrids, species which present a strong tendency to split. Based on the results obtained in four bimonthly inspections of 80 poles (including a control series) and based on the statistical analysis, it was noted that the "Steel-Plates" (Gang-Nail type) contributed to reduce splits in the ends of Eucalyptus poles.
F C Geraldo, J A C Sodré


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


The degradation of wood by metal fastenings and fittings
1972 - IRG/WP 302
As well as the hazards of biological decay, timber used in boat building is subject to the effects of chemical decay associated with the corrosion of metallic fastenings. The title has been deliberately chosen to emphasize that in wooden construction the troubles are not just those of corrosion of the fastenings, but also the destructive secondary effects on the wood caused by the products of the corrosion processes (Plate I). For centuries the world has lived with these troubles commonly referred to as "nail sickness". In contrast to biological decay the chemical decay associated with corrosion is confined to the wood adjacent to corroded fastenings and it is regrettable that in repair work so much wood has to be replaced because of a small percentage degrade in vital spots. Before methods can be devised to overcome these troubles, it is necessary that a better understanding is reached of the mechanisms operating in the degradation process, and recent work at FPRL has thrown some light in this area. The general problem will now be considered in some detail followed by suggestions on possible preventative and remedial measures. Corrosion is the result of an electrochemical process in which the corrosive effect is proportional to the current which flows between areas of potential difference. There are a number of causes of this electrochemical effect such as dissimilar metals in contact, differences in concentration of some chemical factor such as the electrolyte or oxygen availability, stress etc. In all cases areas of different polarity are produced and corrosion only proceeds when the electrical circuit is completed by an electrolyte bridge eg sea water, and a conductor between the anodic and cathodic areas. Figure 1 shows a simple diagram of electrochemical corrosion.
L C Pinion


Deterioration of wood viewed from iron nail
1991 - IRG/WP 2368
Deterioration of nail was graded by a five - rank numerical - rating. The rating of nail moisture content and decay of wood were inspected in a mortal-wall of 34-year-old house. The wood was mostly in decay, when the rating of the nail was above about 4, and the moisture content was above about 20%. Nailed wood specimens kept in several humidity room of 20°C for 4 years showed that the rating of the nail was about 3 in the wood with moisture content 20%. A curve of the rating of the nail against the service year was obtained from the inspection of 524 nails in the mortal-wall. This curve could be a standard life curve of the nail in mortal-wall in the central part of Japan. The curve obtained by connecting the points (4 years, rating 3) and (34 years, rating 4) may be a wood decay warning line in terms of high moisture content. Shear tests for deteriorated nailed joints showed that the load was expressed as function of the slip and the amount of the rust of the nail. The nail used for bevel siding wall is more likely to be influenced by the environmental factors. From the inspection of the nail, the northerly wind was found to be influential to the deterioration the nail in an area of Tokyo.
H Imamura


Untersuchungen zur Prüfung mit Moderfäulepilzen im Vermiculit-Eingrabe-Verfahren
1972 - IRG/WP 214
Im Hinblick auf die Entwicklung eines Prüfverfahrens für die Bestimmung der moderfäulewidrigen Wirksamkeit von Holzschutzmitteln wurden Versuche mit Reinzuchten von Pilzen und mit Vermiculit als Trägersubstanz sowohl mit unbehandelten als auch mit Schutzmittelgetränkten Holzproben durchgeführt. Dabei wurde die Eignung von handelsüblichen, eintachen Einweg-Kunststoffbechern anstelle der bisher verwendeten Glasgefäße erfolgreich erprobt.
W Kerner-Gang, M Gersonde


Investigations on testing with soft rot fungi by the vermiculite-burial method
1972 - IRG/WP 215
With the object of developing a test method to determine the effectiveness of wood preservatives against soft rot attack, tests have been carried out with pure fungal cultures using vermiculite as the substrate for untreated and preservative impregnated wood blocks. In these tests the suitability of common commercial, simple disposable beakers was proved successful as a substitute for the glass bottles used up till now. Comparing the traditional wide-necked bottles with the disposable beakers as test containers for beech and pine sapwood, in the beakers the extent of the wood decay in the beech was 20 to 99 per cent higher than it was using bottles. With pine sapwood in the beakers some values were smaller, some higher than with bottles, altogether the values seemed only negligibly higher using beakers rather than bottles. Tests were carried out to determine the effectiveness against soft rot attack of a copper/chrome/fluorine and a fluorine/chrome/arsenic preservative respectively. In both test series the wood decay caused by individual test fungi or mixed fungal cultures was compared with that caused by the natural microflora of the test soils. In the tests with a copper/chrome/fluorine preservative distinctly higher weight losses were produced in beech blocks in vermiculite by the microflora of the test soil than by particular soft rot fungi. In contrast the tests with the pine sapwood blocks showed practically no difference. The toxic limits determined with individual fungi correspond with those values quoted in the literature for soil burial tests. Also in the tests with a fluorine/chrome/arsenic preservative the pine sapwood blocks used were more severely attacked by the microflora of the test soils than by particular fungi. The toxic values against soft rot attack were of the same order as determined 10 years ago in spite of the use of a different type of soil.
W Kerner-Gang, M Gersonde


Performance of Fasteners in Treated Wood: A Comparative Study
2009 - IRG/WP 09-40465
Fastener performance is an important property for treated wood. Published data on screw and nail performance for different preservative systems currently on the market are, however, limited. In this study, screw and nail withdrawal strength for southern pine wood treated with ACQ (above ground and ground contact), MCQ (above ground and ground contact), borate (disodium octaborate tetrahydrate – DOT), and untreated southern pine control were tested at air dry and water-soaked conditions based on ASTM standard D1037. Individual sample density and surface hardness were also measured. The relationship among screw and nail withdrawal strength, density, hardness, and moisture content was established for various preservative systems.
Q Wu, T Shupe, J Curole, K Ragon, M Voitier, M Freeman, D Ring


The Structural Performance of the Nail Driven into the Decayed Wood
2019 - IRG/WP 19-20652
In late years there are many actions to long-term excellent house realization. We have to consider repair or reinforcement for long-term and safety use of wooden house. There are various studies focused on structural performance of decayed wood. It is important for long-term use of wooden house that structural performance of nailed joint on decayed wood is accurately evaluated. However, there are few studies focused on structural performance of nailed joint on decayed wood. So in this study, structural experiments of the nail driven into decayed wood were conducted, and we tried to make it possible to select a repair method to wooden buildings by quantitatively evaluating the degree of wood deterioration. Brown rot fungus was attached to wood specimens, and they were forcibly decomposed (Decay promotion period: 0, 3, 5, 7, 12, 18 weeks). After the specimen ware air dried, the nails ware driven into them (Figure1) and shear tests were conducted. Confirmation of degree of decay by visual observation · Pilodyn was driven into the tested specimen (Figure2), and the degree of decay was quantified. As a result, the following was clarified. Ⅰ. The maximum load decreased as decay advanced. There was a tendency of slip at the displacement of 2 to 6 mm after load rising, the yield point was observed at the displacement of 6 to 10 mm, and finally the nail was pulled out. Also, as the decay progressed, the variation of the maximum load value increased. Ⅱ. The determination coefficient (R2) of the approximate curve showed the relationship between Pilodyn implantation depth and initial stiffness was small. It is difficult to judge the degree of decay with just the Pilodyn implantation depth. It is necessary to consider the moisture content of the wood and the location where the pin is driven.
N Wada, H Isiyama


The Influence of Wood Included Salinity on Nail
2019 - IRG/WP 19-40863
In the Great East Japan Earthquake that occurred on March 11, 2011, many buildings suffered from natural seawater dipping due to the tsunami. It has become clear that corrosion progresses in nail that had submerged in natural seawater compared to nail that had not submerged in natural seawater. However, processing for this has not been developed. Therefore, in this research, we experimentally explored the possibility of continuous use of nail in wooden building submerged in natural seawater by tsunami. In order to verify the usefulness of rinsing by fresh water, the following experiment was conducted. At first, the wood specimens with nail was submerged in natural seawater, artificial seawater, and sodium chloride solutions. Nails were driven into the wood specimens before submerged and after submerged. Secondly, the rust of specimens, which was rinsed by fresh water or not, was quantified after promoting accelerated rusting. The nail was visually confirmed that the progress of corrosion was suppressed in the nail which was rinsed with fresh water after submerged in natural seawater. However, no significant difference in the degree of corrosion due to the presence or absence of rinsing with fresh water from the quantification of the rust. Each study result was subjected to a significant difference study for each submerged period depending on the presence or absence of rinsing with fresh water. Regarding the calculation results, from this study, there is no significant difference in rinsing with fresh water under any condition, I seemed that it was ineffective. In conclusion, it was confirmed that fresh water rinsing may be inappropriate as a countermeasure against nail that submerged in the natural seawater.
R Nakano, H Ishiyama, K Sakano


Influence of Drying Condition of Wood on Rusting of Nail
2019 - IRG/WP 19-40887
Recently in Japan, the durability of metal joint in wooden structures become important. Revised Building Standard Law was enacted in 2000 and Act on the Promotion of Popularization of Long-life Quality Housing was enacted in 2008 in Japan. Since then, the durability of the metal joints in the wooden houses becomes important. But there are not any detailed regulation for the durability of the metal joint in the wooden structures in Japan. In this study, nails driven into woods, -dried with high temperature, dried with middle temperature, dried with low temperature, natural-dried, and non-dried-, was put in high temperature and high humidity environment in long-term, for clarifying the influence of drying condition of wood on rusting of nails. After that, the shear test was conducted, and the rust on nails was removed for evaluating the mass loss by corrosion. As a result, follows were confirmed. 1. The shear strength of the nail is highest when the weight remaining ratio is about 95%-80%, and when rust progressed, the shear strength decrease. 2. The nails driven into sapwood rust remarkably than the nails driven into heartwood. 3. The nails -driven into woods with natural-dried or non-tried rust remarkably than dried with high temperature, dried with middle temperature, or dried with low temperature.
H Ishiyama, N Wada, T Nishimura, T Mori


Study on Nailed Joint with Iron Contamination. Part1: Shear Performance of Nailed Joint with Iron Contamination
2019 - IRG/WP 19-50349
In Japan, The building standard law was amended in 2000.1) The use of metal joint was obligated by this law. Since then, metal joints have been largely used for wooden buildings. Also, Act on the Promotion of Popularization of Long-life Quality Housing was enacted in 2009 and leaving Long-life Quality Housing has been focused on2). However, leaving houses to posterity for a long time causes several problems. One of the problems is degradation of members. When timbers and metals react, iron contamination is caused. This phenomenon has been considered problematic. This study verifIES what kind of influence iron contamination have which is caused by chemical reaction with timbers and metals to structural performance of timber and nails. Iron contamination and rusts were forced to be formed on the test specimen represented a connection of column and plywood on shear wall, and shear performance was checked at each stage. Regardless of the presence or absence in preservative treatment, when weight remaining ratio went down, maximum shear capacity increased. When weight remaining ratio went down less than 80%, the maximum shear capacity decreased. When iron contamination was formed, the maximum shear capacity increased. But, Pu×0.2/Ds which indicate ductIlity declined. Rust accelerated quicker on the specimen to which preservative treatments were applied than on the specimen to which no preservative treatments were applied.
R Nakano, D Nakano, H Ishiyama


Study on Nailed Joint with Iron Contamination. Part2: Elucidation of the Occurrence Condition of Iron Contamination
2019 - IRG/WP 19-50350
In recent years, efforts towards wooden buildings are progressing in Japan. And many woods are used in various places. However, various problems have also occurred in wooden buildings. One of the problems is iron contamination which appears when wood and metal chemically react. At present, tree species that are prone to iron contamination and components that cause iron contamination are clarified. However, the actual weather conditions under which iron contamination occurs are unknown. In this study, conditions of occurrence of iron contamination verified seven test methods. The test method is difference in water quality, difference in temperature, the influence of water entering from the butt end of plywood, the amount of rainfall and iron contamination occurrence time, the difference between sapwood and heartwood, the difference in the distance the butt end and the comparison of how to hit nails. By the results of this test, the water quality and water temperature had little effect on the occurrence of iron contamination within the conditions of this test. However, when the temperature of the environment to be dried was low, the occurrence of iron contamination remarkably decreased. The colour intensity and extent of iron contamination change with rainfall amount. Iron contamination spreads up to the top 10 mm of the nail. The state of the nail after driving the nail into the occurrence of iron contamination does not affect. However, iron contamination did not appear on the surface of the nail implanted deeply into the plywood.
D Nakano, R Nakano, H Ishiyama