Material selection and mix design considerations for constructing asphaltic roads and runways in Canada's north
The design of practical asphaltic roads and runways in Canada's north is very difficult due to the harsh environmental conditions under which the material needs to be placed in the field, the severe temperature loads to which the pavement is exposed, and the difficulty and (or) cost of obtainin...
Published in: | Canadian Journal of Civil Engineering |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1991
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Subjects: | |
Online Access: | http://dx.doi.org/10.1139/l91-051 http://www.nrcresearchpress.com/doi/pdf/10.1139/l91-051 |
Summary: | The design of practical asphaltic roads and runways in Canada's north is very difficult due to the harsh environmental conditions under which the material needs to be placed in the field, the severe temperature loads to which the pavement is exposed, and the difficulty and (or) cost of obtaining appropriate materials. This paper summarizes the current state-of-the-art in terms of the selection of materials and the design of mixes for the construction of asphaltic pavements in Arctic and sub-Arctic climates. It is shown that the temperature susceptibility of the asphalt cement, the curing rate of cutback liquid asphalts, and the transport of asphalt emulsions at low temperatures are the main problems associated with selecting a binder material. Emulsions appear to be the best suited for use in cold climates, but there is little experience with their use in the far north. In addition, it is indicated neither standard nor the modified Marshall nor the Hveem tests provide ideal tests for selecting the optimum binder content, the degree of curing, the required aerating, or the amount of mixing water for designing asphalt mixes. Key words: asphalt pavements, northern roads, mix design, material selection. |
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