Your search resulted in 17 documents.
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
Incorporating insect behaviour in standard tests of wood preservatives - A possible way to reduce pesticide loadings
2000 - IRG/WP 00-20190
The application of wood preservatives to protect timber against insect infestation is common practice world wide. The effectiveness of wood protecting insecticides is usually determined in various standard tests. Depending on the target pest species and the test method, larvae of different developmental stages and sizes or adult insects are exposed artificially to the insecticide-treated commodity...
H Hertel, R Plarre
Ekki heartwood - is “Durable”
2002 - IRG/WP 02-10444
Severe decay damages of bridges made of ekki (Lophira alata Banks) wood which is classified as a durable species in the EN 350:2 as already reported at the 31 IRG annual meeting. This paper deals with results of long-term decay tests of ekki heartwood specimens using 3 isolates (Loweporus tephroporus 2 strains and a fungus of other sp. from damaged ekki bridges) and Trametes versicolor as a refere...
S Doi, R Itoh, S Horisawa
Soft-rot control in hardwoods treated with chromated copper arsenate preservatives. Part 3: Influence of wood substrate and copper loadings
1977 - IRG/WP 2100
The hypothesis is proposed that hardwoods need more chromated copper arsenate (CCA) than softwoods to protect them from soft-rot attack mainly because hardwoods are more readily consumed by soft-rot fungi. Simple model systems, using copper-supplemented agar or groundwood pulp treated with CCA showed that fungi tolerated more toxicant (copper) as more available substrate (malt) was provided. Soft-...
M A Hulme, J A Butcher
Severe decay damages of bridges made of ekki (Lophira alata) wood known as a durable species
2000 - IRG/WP 00-10383
Bridges made of ekki (azobe, bongossi, Lophira alata Banks et Gaertn.) timbers were severely decayed only 10 years after the construction possibly caused from no maintenance for the periods. The reason of no maintenance is due to the misunderstandings on wood durability against wood-decaying fungi. Some civil-engineers and architectures understand "durable species" means "absolutely decay-durable ...
S Doi, T Sasaki, Y Iijima
Leaching from CCA-treated wood submerged in seawater: Effect of high loadings, and a comparison between laboratory and marine conditions
1996 - IRG/WP 96-50080
This study of leaching examined the following variables: CCA loading; marine versus laboratory exposure and length of submergence. Blocks of Pinus sylvestris were treated to a range of nominal retentions from 15 to 50 kg/m³. Each block was then divided into three cubes and all transverse faces were sealed. All cubes were allowed to fix at ambient temperature for a minimum of one week. One set of ...
R M Albuquerque, S M Cragg, J D Icely
Monitoring a Timber Bridge in Norway
2004 - IRG/WP 04-40282
We have instrumented three different timber bridges in Norway for the Norwegian Public Roads Administration. The goal was to learn more about the properties of timber bridges. We have instrumented Evenstad Bridge, Daleråsen Bridge and the last year Flisa Bridge. All bridges are have creosoted glulam trusses and creosoted stress laminated deck. Evenstad and Flisa have an asphalt deck on top, while...
F G Evans
Cost effective extension of service life of bridge tie (sleepers) - Effectively applying borate during Boulton conditioning and treatment with copper naphthenate
2014 - IRG/WP 14-30637
Current longevity of creosote treated wooden bridge ties in the South Eastern US is about 15 to 25 years, which is well below of the average service life of 33-50 years of railroad ties. Such short service life increases costs associated with maintenance of railroads including bridge down time for tie replacement as well as the cost for the new ties themselves. Because of this, many railroads are...
J D Lloyd, T Chambers, J-W Kim
Creosote leaching from timber bridges in Norway – a practical classification approach
2016 - IRG/WP 16-40744
Creosote is widely used as a wood preservative for highway timber bridges in Norway. However, excessive creosote leaching at various highway timber bridge sites leads to a bad reputation for the use of creosote treated timber constructions and the use of wood in general. Macro- and micro anatomical factors such as amount of heartwood, annual ring width, annual ring orientation, ray- height and com...
A Treu, K Zimmer
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
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
Borate and Copper Naphthenate Dual Treatment of Bridge Timbers-Borate movement over time
2017 - IRG/WP 17-40795
Preservative treated wooden bridge ties in the South Eastern USA have a service life of about 15 to 20 years, which falls well below the average service life of 40 years of railroad cross ties (sleepers). It has been shown that cross tie life is significantly extended using borate dual treatment and this is now commercialized in bridge timbers using borate inserts. In previous research, it was dem...
J-W Kim, J D Lloyd
Performance of Norway spruce bridge in North-West Spain after 12 years exposure
2017 - IRG/WP 17-40796
Across Europe is very common to find bridges build in sawn and glue-laminated wood. Most of these bridges used softwood wood species such as: fir, spruce, larch and pine.
In Spain wooden bridges, became more and more popular since nineties, when sawn and glue-laminated wood were utilized for building exterior wooden structures in overall Spain.
This material, sawn and glue-laminated wood, are ma...
D Lorenzo, J Fernández-Golfín, M Touza, M Guaita, A Lozano, J Benito
Dual Borate and Copper Naphthenate Treatment of Bridge Timbers:- Potential Performance Enhancements and Cost Savings
2017 - IRG/WP 17-40797
Dual treatment technology combining diffusible preservatives with oil borne preservatives, widely used for crossties in the USA, has now also been commercialized with bridge ties/timbers. In order to understand the implications of these changes, the historic service life of creosote treated bridge timbers in northern and southeastern USA were considered as well as field test data for both creosote...
J Lloyd, C Brischke, R Bennett, A Taylor
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
Performance of wood exterior structures above ground in Spain built with softwood species. The situation case of a shelter bridge
2018 - IRG/WP 18-40844
Across Europe is very common to find wood exterior structures build in sawn and glue-laminated wood. Most of these exterior wood structures use softwood wood species such as: fir, spruce, larch and pine. In Spain exterior wood structures, became more and more popular since nineties, when sawn and glue-laminated wood were utilized for building exterior wood structures in overall Spain. This paper s...
D Lorenzo, M Touza, J Fernández-Golfín, A Lozano, J Benito