Your search resulted in 1251 documents. Displaying 25 entries per page.
Modelling of moisture content in timber bridge details
2017 - IRG/WP 17-20613
The design of details is an important aspect in durability design of timber bridges. Details are often considered the weakest points in bridges due to their tendency to trap and accumulate moisture and thus facilitate decay. When designing maintenance plans and inspection intervals, it is important to know how design choices will come to influence the service life. Moreover, service life and wood ...
J Niklewski, C Brischke, E Frühwald Hansson, L Meyer-Veltrup
Comparative Durability of Timber Bridges in the USA
2017 - IRG/WP 17-20615
As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was jointly administered by the ...
J P Wacker, B K Brashaw
Overview of the treated wood quality control program in the United States with the recent challenges and advances
2017 - IRG/WP 17-20616
In the past two decades, there have been significant and rapid changes in wood protection technologies for residential applications which have moved away from long established heavy duty metal oxide based products such as chromated copper arsenate (CCA). The successor generation of wood protection systems usually contain copper as the primary biocide, in combination with carbon-based co-biocides s...
L Jin
Moisture content as a quality control parameter in thermally modified timber production
2017 - IRG/WP 17-20622
Quality assurance (QA) or factory production control (FPC) is necessary to ensure a proper production process. The requirements of QA/FPC can result from EN and national standards, quality assurance systems, or producer-specific rules.
TMT producers must ensure that the process was correct, and to ensure traceability of products. In addition to the electronic records, the material should be che...
W Scheiding, H Turkulin, S Stein
An experimental study of mould growth and wood decay in timber frame walls
2017 - IRG/WP 17-20623
This paper deals with parameters related to the occurrence of mould growth and wood decay in timber frame walls. In a first part, the hygrothermal conditions inside a timber frame wall finished with brick veneer cladding are analysed to get an idea of possible moisture related problems. It is shown that, based on the VTT mould prediction model, there is a mould risk on the interface between the in...
M Vanpachtenbeke, J Van den Bulcke, I De Windt, J Langmans, S Roels, J Van Acker
Ensuring Quality of Treated Wood – Regulations, Certifications and Associative Background in the Field of Wood Protection in Europe
2017 - IRG/WP 17-20626
Beside legal requirements, buyers and end-users of wood preservatives and/or of treated wood and wood-based materials may require additional warranties regarding the quality and the performance of the products available on the market. These greatly enhance the confidence of end-users and the chance for a product of being marketed with a quality label. Additionally, quality control systems and trai...
M Kutnik, M Klamer, E Melcher
Development of Potentiometric Enzyme Biosensor for Detection of Permethrin Preservative in Treated Wood
2017 - IRG/WP 17-20628
Characteristics of a potentiometric enzymatic biosensor based on a pH transducer for permethrin detection in treated wood are reported in this article. The transducer contained a plasticiser-free methacrylic-acrylic membrane immobilised with hydrogen ionophore and a lipophilic salt. A poly(2-hydroxyethyl methacrylate) (pHEMA) was used to immobilise carboxylesterase for the detection of permethrin....
M Nasir Mat Arip, C Tan, Gan Kee Seng
Efficacy of Erythropleum suaveolens (potrodom) and Distemonanthus benthamianus (bonsamdua) water extractives on the durability of five Ghanaian less used timber species of varying perviousness and retentiveness
2017 - IRG/WP 17-30705
Conventional wood preservatives are not only toxic to target bio-deterioration organisms but also to humans, other organisms and the environment. In an effort to find preservatives that are less toxic or non-toxic to man, other organisms and the environment, efficacy of branch bark and heartwood water extracts (0.65 g/ml) of Erythropleum suaveolens (potrodom) and Distemonanthus benthamianus (bonsa...
A Asamoah, K Frimpong-Mensah, C Antwi-Boasiako
Field Performance of Refractory Species Treated with MCA
2017 - IRG/WP 17-30706
Micronized copper azole (MCA) has been used extensively over the past decade to preserve southern pine, and other wide sapwood species. Treatment of refractory species is less common, in part due to concerns about treatability and resulting efficacy. To address these concerns, white spruce and Pacific silver fir stakes, and lodgepole pine and red pine posts, were pressure-treated with multiple ret...
R Stirling, J K Ingram, P I Morris
Copolymers of tannin extracts as wood protection agents
2017 - IRG/WP 17-30709
Wouldn´t be a dream to preserve wood with the substances which the nature already synthesizes for protecting itself? The idea we would like to pursue is simple: Increase the concentration of these substances, the tannins, trying to fix them properly in wood. It appears easy but it is not. Sensibility against leaching, fungal decay and weathering were observed. In this paper new flavonoid co-polym...
G Tondi, L Sommerauer, A Oberle, A Petutschnigg, M-F Thevenon
Effects of Nano-Wollastonite Impregnation on Fire Properties of Some Thermally-Treated Solid Wood Species
2017 - IRG/WP 17-40771
The effects of nano-wollastonite (NW) suspension impregnation on the fire-retarding properties of heat-treated solid wood of three species (beech, poplar, fir) were studied. Heat treatment was performed at two temperatures of 180 °C and 200 °C. Impregnation was carried out at a pressure of 3 bars for 30 min. The fire properties included ignition time, glowing time, back-darkening, back-splitting...
H R Taghiyari, R Hossinpourpia, S Adamopoulos, A Jahangiri, D Rabie
Dimensional Stability of Melamine Formaldehyde-Treated Southern Pine
2017 - IRG/WP 17-40774
The objective of this preliminary study was to evaluate the influence of different levels of melamine formaldehyde (MF) and curing cycle on the dimensional properties of southern pine. Thirty samples for each combination of treatment and curing regimen plus untreated controls and controls subjected to the same curing regimen were tested. Shrinkage/swelling coefficients showed that up to 60% ASE c...
H M Barnes, L S Sites, T S F A França, M G Sanders, F J N França
Evaluation of timber bridges with special consideration of detail design
2017 - IRG/WP 17-40781
Since 1997 the use of wood in bridge construction has been increasingly criticized by the Hamburg federal state authority supposedly because of shortened service life due to decay. With regard to wood research, however, it is often suggested that use of timber is suitable for weathered structures as long as constructive protection measures will be observed. In order to unravel the reasons for the ...
K Robbers, J Fromm, E Melcher
Agar block durability test of plywood made of neem (Azadiracta indica) leaves treated veneer using two white rot fungi
2017 - IRG/WP 17-40782
This study has been undertaken to investigate the durability of plywood made from non-durable wood (simul, Bombax ceiba) veneer treated by neem (Azadiracta indica, A. Juss.) leaves. The veneers were treated with cold and hot water solution of neem leaves of different concentrations (10%, 5%, 2.5%) and treatment durations (1, 2, 3 days) for cold water and 20, 40 and 60 minutes for hot water. The pl...
K Akhter, M A Hashem, S Akhter
Prefacricated modular wooden bridges
2017 - IRG/WP 17-40785
The bridge consists of simple, identical pre-fabricated triangular wooden panels joined top and bottom to make up trusses. These trusses are in turn joined together side by side in pairs and are braced to one another to create a girder construction. The deck is carried on top of the trusses, an arrangement which has several advantages for such an uncomplicated structure. It is built up on site, af...
L Jayanetti
Solid Timber Bridges – Latest Developments
2017 - IRG/WP 17-40788
The technology of gluing in wood construction has evolved considerably in recent years. This has been shown especially in timber bridges that Glulam is now the main building material. A further development is the so-called block gluing, which provides a good basis for supporting structures. Numerous bridges, especially in central Europe, appeal by unique design and monolithic and solid construction. These structures base on two main developments: block lamination of glulam and the composite of timber and concrete to one structural system.
F Miebach
The potential and the challenges of acetylated wood in timber bridges - experiences from an ongoing project
2017 - IRG/WP 17-40792
Acetylated wood is known to be a durable and dimensional stable alternative for high performance materials, and has high potential for exterior timber structures. Research has shown that acetylated wood can be effectively bonded by various adhesive types. However, one of the most common used adhesives for timber constructions, Melamine Urea Formaldehyde (MUF), shows a high degree of delamination o...
A Treu, R Bredesen, F Bongers
In-service performance of treated plywood bridge decks in Australia
2017 - IRG/WP 17-40794
Engineered wood products have a long history of use in bridge construction in Australia. The first bridges incorporating chemically protected engineered wood components were installed in the 1850’s and some survive to this day. Preservative treated plywood bridge deck panels have been employed since the 1980’s as a replacement for the more traditional hardwood plank decks. This paper report...
M A Powell
The Effects of Pre-Microwave Treatment on Retention Levels And Some Mechanical Properties of Spruce Wood Treated with CCA
2017 - IRG/WP 17-40800
Microwave (MW) treatment of wood has been evaluated in recent years for different purposes by several scientists. Microwave conditioning improves permeability, reduces density and heat conductivity and changes dimensional stability. Furthermore, it could even improve the permeability of refractory wood species such as spruce and Douglas fir. In this study, MW pre-treatment was applied to spruce wo...
E D Gezer, S Kuştaş, S Durmaz
A summary of history and use of timber bridges in New Zealand
2017 - IRG/WP 17-40801
Wooden bridges have been an important part of road and rail networks in New Zealand. While wooden structures have largely been replaced by concrete and steel on major arteries they still have a place where lightweight, easily assembled structures are needed. These timber bridges may also be a cheaper alternative to other materials in roads which carry relatively low traffic loads. In the last ten ...
D Page, T Singh
Review on protection of timber bridges in Norway and other countries
2017 - IRG/WP 17-40809
Wood plays a major role in design and construction of modern bridges in Norway. Typical elements of those bridges are double impregnated glued laminated members, stress laminated timber decks, slotted-in steel plates, metal cladding of the surfaces of loadbearing members, and cross girders made of steel. Selected examples of timber bridges in Norway are presented. This review paper gives an overvi...
K-C Mahnert, U Hundhausen
Durability of energy efficient wooden buildings: a building physical point of view
2017 - IRG/WP 17-40812
The drive for more energy efficient and sustainable buildings resulted in an increased popularity of wooden buildings, even in countries with a masonry tradition. Often guidelines and prescriptions then are copied from other countries. Different climatic boundary conditions and tradition of finishing, though, do require different moisture tolerance criteria. This is clearly the case for water vapo...
S Roels, J Langmans
A Green and Novel Technology for Recovering Copper and Wood from Treated Wood Waste – Part II: Optimization, copper metal recovery, and process design
2017 - IRG/WP 17-50326
The US consumes 70 million pounds of copper and produces 580 million cubic feet treated wood annually. The EPA disallows burning and reusing treated wood waste due to health/environmental concerns. Vast quantities of copper and wood are landfilled. Two safe and low cost extraction systems, citric acid and ammonium citrate, were identified in Part I of this study. In Part II of the study, effects o...
S Chen, R Patel
Review of Leaching Experiments of CCA-Treated Wood and Wood Treated with Copper-based Alternatives
2017 - IRG/WP 17-50330
The objective of this study was to compare leaching rates of various wood preservatives from treated wood and the tests used to gather this information. The preservatives compared included CCA and the copper-based alternatives, MCQ, ACQ, and MCA. The tests compared included AWPA E11, SPLP, TCLP, and environmental leaching tests. Among all of the tests evaluated, environmental tests most closely si...
A Jones, J Marini, H Solo-Gabriele
Uncertainty in life cycle assessment of preservative treated wood – copper and freshwater ecotoxicity
2017 - IRG/WP 17-50331
Life cycle assessment (LCA) is a method for quantifying the environmental impacts of a product over the life cycle. In the last years, there have been a growing application of LCA in developments of environmental product declaration (EPD), which is utilised by professional procurement of materials for buildings. For legislative issues, LCA have also been used to assess application of creosote to t...
L G F Tellnes