Your search resulted in 1472 documents. Displaying 25 entries per page.
Natural decay resistance of some lesser-used tropical hardwoods from Ghana
2002 - IRG/WP 02-10438
Ghana is a tropical African country that is rich in diverse timber species. In order to reduce over-exploitation of the popular timber species and increase the resource base for the wood industry, lesser-used or lesser-known timber species are being promoted locally and for export. To do this successfully, it is essential to determine the physical, mechanical and biological properties of these tim...
S A Amartey, F R Hanson
Durability of Wood Plastic Composites Relative to Natural Weathering and Preservative Treatment With Zinc Borate
2005 - IRG/WP 05-40316
Wood-Plastic Composites (WPCs) used for decking have experienced dramatic increases in North America, averaging 25% growth per annum since 1998. A key factor contributing to this growth has been the successfully communicated message that they are "virtually maintenance free". The common perception being that the wood fiber is completely encapsulated by the thermoplastic resin, minimizing the pot...
M E Mankowski, F M Ascherl, M J Manning
Improvement of wood decay resistance by tannin impregnation
1991 - IRG/WP 2380
The fungical effect of tannins is appraised after exposure of treated woods samples to wood rotting fungi. A screening-test is carried out with several solutions containing extracts of two kinds of tannins; a condensed tannin derived from Quebracho heartwood (Schinopsis sp.) and a hydrolyzable one extracted from chestnut heartwood (Castanea sativa Mill). If a fungicidal action was indeed found it ...
D Dirol, A Scalbert
Soft rot decay of Belian (Eusideroxylon zwageri) wood
1995 - IRG/WP 95-10119
The heartwood of Belian (Eusideroxylon zwageri), an East Malaysian timber species, is naturally durable due to its certain unique anatomical features and high content of extractives. The timber can tolerate years of exposure to hazardous conditions in ground contact and other situations without any significant loss in its strength. A few Belian transmission poles sampled from one locality in Saraw...
A H H Wong, A P Singh
Biocidal screening method of wood extractives by a direct use of cellulose TLC plate
2001 - IRG/WP 01-20226
Most of the methods to evaluate the biological durability of woods have focused on decay fungi and termite as deteriorating organisms and it is well known that one of the most important factors affecting the biological characteristics of wood is extractives. Bioassays for evaluating the biological activities of wood extractives have been mainly conducted with treated filter papers for termites or ...
R Yusiasih, T Yoshimura, T Umezawa, Y Imamura
Decay and termite durabilities of heat-treated wood
2004 - IRG/WP 04-40272
Decay and termite resistances of Plato-treated timbers were evaluated using a modified JIS decay test method, feeding test in a laboratory scale and a field exposure against Reticulitermes speratus (Kolbe) or Coptotermes formosanus Shiraki. The results showed that no significant decay durability of the
treated timbers although mass loss from decay slightly decreased in case of treated timbers. ...
S Doi, K Hanataa, E Kamonji, Yuuji Miyazaki
Assessment of wood decay in small-scale unsterile soil-bed tests
1997 - IRG/WP 97-20111
This study is concerned with the investigation of wood decay in small-scale unsterile soil-bed tests. Tests were performed with untreated heartwood samples from five hardwood species of different natural durability classes ranging from highly perishable to very resistant. Our results confirmed the critical role of soil moisture content on wood decay. The highest decay rates were observed at moistu...
L Machek, A M Derksen, R Sierra-Alvarez
Durability of five wood species against Coriolus versicolor
1992 - IRG/WP 92-1578
The durability of following five wood species Zelkova carpinifolia, Ulmus glabra, Carpinus betulus, Acer trauvetteri and Pterocarya fraxinifolia were studied against Coriolus versicolor under laboratory conditions according to DIN 52176 standards. Zelkova caprinifolia shows a reduction in weight of 2.19%, Ulmus glabra 41.69%, Carpinus betulus 45.64%, Acer trauvetteri 53.05%, and Pterocarya fraxini...
S M Kazemi
Relationship of wood durability and extractives
2003 - IRG/WP 03-10493
The durability of the following five wood species, Zelkova carpinifolia, Ulmus glabra, Pterocarya fraxinifolia, Carpinius betulus and Acer laetum, were studied. Wood blocks were exposed to Coriolus versicolor under laboratory conditions according to DIN 52176 standard. After 16 weeks incubation the heart wood of Z carpinifolia showed 2,19 % weight loss, U glabra 41,69 %, C betulus 45,64 %, A laetu...
S M Kazemi
Resistance of various wood species against decay by Coniophora cerebella (Pers) Duby and Lenzites trabea (Pers) Bres
1976 - IRG/WP 142
Both fungi, Coniophora cerebella and Lenzites trabea, are important destroyers of timber. Coniophora often occurs inside buildings and Lenzites trabea has been observed on southern facades of buildings, on balconies and window frames. In most instances that we investigated coniferous timber had been decayed. But both species are known to attack also various hardwoods. For this reason tests similar...
O Wälchli
Soft Rot Decay of Cengal (Neobalanocarpus heimii) Heartwood in Ground Contact in Relation to Extractive Microdistribution
2003 - IRG/WP 03-10501
The heartwood of cengal (Neobalanocarpus heimii, fam. Dipterocarpaceae) is naturally durable. A square-sawn utility pole specimen of cengal heartwood, after 30 years in ground contact, showed 10-15 mm surface decay all around the ground line position, accompanied with isolated surface termite attack at the decayed region. Light and transmission electron microscopy (TEM) of the decayed regions prov...
A P Singh, A H H Wong, Yoon Soo Kim, Seung-Gon Wi, Kwang Ho Lee
NIR spectroscopy for rapid estimation of decay resistance
2004 - IRG/WP 04-20294
In Scandinavia Scots pine (Pinus sylvestris L.) is an important commercial tree species. Its heartwood has traditionally been used in constructions exposed to risk of decay. In a laboratory experiment Scots pine wood specimens sampled from inner heartwood, outer heartwood and sapwood were exposed to the brown rot fungus Poria placenta. In general outer heartwood was more resistant than inner heart...
P O Flæte, E Ystrøm Haartveit
Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions...
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek
Variation of natural durability of sugi (Cryptomeria japonica) wood in 15 clones examined by decay test (Preliminary report)
2004 - IRG/WP 04-10526
Natural durability of wood in 27 trees from 15 clones of sugi (Cryptomeria japonica)　 was investigated by an accelerated decay test. Thirty years old trees were collected from a clonal trial in Ibaraki prefecture, Japan. Natural durability is usually evaluated in heartwood. Mass losses of heartwood caused by a brown rot decay fungus, Fomitopsis palustris and a white rot decay fungus, Py...
K Yamamoto, A Tamura, R Nakada
Is laboratory testing of decay resistance questionable as a single criterion for natural durability?
1996 - IRG/WP 96-20096
In a laboratory test set up over 20 hardwood species were evaluated according to the European Standard EN 350-1 including Basidiomycete and soft rot testing. Half of the species used were of a known natural durability. The Basidiomycete testing was carried out using Coriolus versicolor, Gloeophyllum trabeum and Coniophora puteana in a malt agar test similar to EN 113. From this test it was not pos...
J Van Acker, M Stevens, T Van Cauwenberghe, T Seynaeve
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of ...
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
A dynamic approach to assess the modulus of elasticity in wood decay testing
1998 - IRG/WP 98-20139
In this study, the changes in elastic behaviour and mass losses of different hardwood and softwood species exposed to decay in a laboratory soil tests were assessed. Wood decay was monitored using different assessment methods, namely: mass loss and changes in elastic behaviours (MOE) determination. Elastic changes were determined by static and dynamic methods, for the latter, acoustic technique wa...
L Machek, H Militz, R Sierra-Alvarez
Evaluating the resistance of wood-based panel products to fungal attack
1995 - IRG/WP 95-20071
At present there is considerable disagreement among national research institutes within Europe and panel product manufacturers on the most appropriate method of testing and indeed the need for specific biological durability testing. This paper seeks to place before a broader international audience, the issues related to development of a European standard for evaluating the resistance to fungal dec...
R G Lea, R W Berry
The effect of alternative pre-conditioning procedures on the durability of wood based board materials to decay fungi
1997 - IRG/WP 97-20105
In the biological testing of wood based board materials it has been shown that exposure of boards in a closed vessel system may lead to inaccurate results due to the build up of volatile substances that inhibit the test fungi. It is thought that this is a transitory effect of freshly manufactured boards. In the European standard for testing fungal durability of board materials which is currently u...
S F Curling, R J Murphy, J K Carey
The improvement of wood durability by retification process
1993 - IRG/WP 93-40015
A material with new properties is obtained by retification process. It consists of a light pyrolysis of wood which becomes more stable and especially more resistant to fungal attack with few decrease of mechanical properties. Tests were carried out on three susceptible wood species (Poplar, Spruce, Fir) that are used in construction and are difficult to treat with wood preservatives. Retified wood...
D Dirol, R Guyonnet
Relative merits of laboratory and field tests for assessing wood decay resistance
1993 - IRG/WP 93-20009
Laboratory and field trials have long been employed for assessing natural durability of a variety of wood species, but there is a continuing debate concerning the relative merits of approach. While laboratory tests provide carefully controlled conditions for decay, they are often criticized for being too artificial to produce meaningful results. Conversely, field trials often vary widely between t...
T C Scheffer, J J Morrell
Some studies on fungal deterioration of rubber wood (Hevea brasiliensis)
1980 - IRG/WP 2140
For the sreening of anti-stain chemicals trials with selected agricultural fungicides and new chemicals were carried out. Botryodiplodia theobromae, Aspergillus sp. and Penicillium sp. were used at test organisms. For testing the durability of rubber wood (Hevea brasiliensis) suitable local rotting fungi (Basidiomycetes), based on high degrading power, which may later be employed in standard tests...
A Sujan, A G Tan, M Stevens
Chitosan for wood protection - state of the art
2005 - IRG/WP 05-30378
The aim of this paper was to give a state of the art description of chitosan as a wood protecting agent. Chitosan is a metal free natural compound derived from crustacean shells and is under evaluation as an environmentally benign wood protecting agent. Information from journals states that chitosan may act both fungistatically and at higher concentrations, as fungitoxic, but the mode of action is...
M Eikenes, G Alfredsen, E Larnøy, H Militz, B Kreber, C Chittenden
The high decay resistance in the sapwood of the naturally durable Malaysian hardwood Belian (Eusideroxylon zwageri)
2001 - IRG/WP 01-10410
It has long been assumed that the observed natural durability of the heartwood in certain timbers is perhaps associated with a relatively lower decay susceptibility also of the sapwood of these species. While the heartwood of Belian is reputedly highly decay resistant among the tropical hardwoods of Southeast Asia, laboratory decay tests reported in this paper have also confirmed the high decay re...
A A H Wong, A P Singh
Natural durability of larch heartwood against decay
1997 - IRG/WP 97-10201
Larch heartwood has been promoted in Sweden and in other European countries as an alternative to preservative treated timber. It has even beeen stated that larch heartwood is more durable than preservative treated timber. This paper presents a compilation of facts from scientific reports on the durability of larch heartwood. Some recent data from this department are also reported. All data suggest...
T Nilsson