IRG Documents Database and Compendium

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Preliminary attempts towards the development of a small scale termite rearing chamber. Progress report
1983 - IRG/WP 1203
The results suggest that there is no evidence that the volume of the rearing chamber plays a part in the settlement of a colony. These rearing chambers present a factor of productivity (final enumeration)/(initial enumeration) of roughly 2 after one year. 90% of the colony survived. This method of breeding can be considered as feasible and cheap.
M Argoud, J C Palla, R Sternalsky

Preliminary attempts towards the development of a small-scale termite rearing chamber
1982 - IRG/WP 1148
The paper suggests how to prepare a small-scale rearing chamber for termites which might be used for testing the effectiveness of possible termiticides. A technique for breeding the termites is suggested.
M Argoud, J Mocotte, R Sternalsky

Moderate temperature fixation of CCA-C
1989 - IRG/WP 3522
Several Canadian treating plants are using moderate temperature (40-60C°) fixation chambers to reduce drippage and leaching from fresh CCA treated wood. In this study, chromium reduction and surface leaching properties of CCA-C treated red pine (Pinus resinosa) pole sections were monitored during exposure to temperatures of 50-60C° and 90-100% RH conditions. Chromium-VI concentration in the absorbed treating solution dropped significantly during the treating cycle to 50-60% of that in the free treating solution. The chromium-VI concentration also dropped with increasing depth in the pole. During the six to 24 hour fixation cycle the Cr-VI concentration dropped steadily especially in the outer layers of the pole, but even after 6 hours, a significant amount of Cr-VI was observed at all measured depths. After 12 hours, Cr-VI was only barely detectable at all depths. The leachate analyses were consistent with the Cr-VI results, indicating reduced but still significant surface losses while Cr-VI could still be detected.
P A Cooper, Y T Ung

Evaluation of the efficiency of industrial kiln type CCA fixation chambers
1996 - IRG/WP 96-40063
Six commercial CCA treating plants in Canada were assessed for the fixation efficiency of their hot air fixation chambers. The wood temperature was measured with thermocouples over the fixation period at different locations in the chamber and at the end of the fixation cycle, the degree of chromium fixation was determined by a boring leaching procedure. There was a great variation in the effectiveness of the chambers, related to the heat transfer efficiency of the kilns. Both an adequate steam supply and efficient air circulation are essential to ensure quality fixation in a reasonable time frame. In plants without this, the wood deep in the lumber piles is still in a mainly unfixed state when removed from the fixation chamber. In contrast, for CCA treated wood allowed to fix under ambient temperature conditions, the interior of bulk piled lumber fixes faster than the outer wood or stickered wood. This results from the cooling effect of water evaporation from the exposed lumber as it dries.
A Taylor, P A Cooper

Quantification des émanations de substances dans l'air ambiant a partir des bois traités
1993 - IRG/WP 93-50001-27
Pesticides on wood for the purpose of its protection may evaporate. Eventual toxicity of such emanations justifies risk assessment procedures for indoor air in building. This document describes bench scale tests based on the technique of chambers developped by CTBA/BIOTEC to determine the amount of pesticides and associated substances released to the ambient air. Results obtained with various pesticides are reported. The part played by physico-chemical parameters including formulation is also described. Conclusions are that relevance of risk assessment procedures must pay atention to formulation, wood and in service conditions and that specific models might be necessary.
H Sageot, M Lamour

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 seeking non-wood alternative ties, even at vastly elevated initial cost. The objective of the study was to see if it is possible to apply borate as part of a dual treatment with copper naphthenate, in order to increase the service life of wooden bridge timbers at minimal additional cost. Green hardwood ties were ported, borate treated, and then Boulton treated with copper naphthenate at a commercial tie treatment plant in Pennsylvania. Diffusion of borate within the wood appeared to be significantly enhanced by the elevated temperature and steam generated during the Boulton cycle and subsequent pressure treatment with copper naphthenate. The achieved retention and penetration of borate and copper naphthenate met AWPA standard retentions and AREMA guidelines. The longevity of ties should be significantly increased by protecting the heartwood with disodium octaborate tetrahydrate (DOT) and the sapwood with copper naphthenate. The results suggested that hardwood ties can be successfully treated with borate during a Boulton cycle and should allow the continued effective use of sustainable wooden bridge timbers.
J D Lloyd, T Chambers, J-W Kim