Pavement shoulder cracking is a reoccurring problem in Canada’s North. In an effort to have a better understanding of its causes and prevention methods, FPInnovations partnered with the Yukon government and TenCate Geosynthetics on innovative research that’s led to a soon to be published paper and presentations at national and international conferences.
FPInnovations’ Papa-Masseck Thiam and Allan Bradley, research engineers in the roads and infrastructure group, recently co-authored a research paper accepted for publication in the Canadian Geotechnical Journal with René Laprade of TenCate Geosynthetics and Muhammad Idrees, Stuart Drummond, and Paul Murchison of the Yukon government’s transportation engineering branch. The paper is titled, “Mitigating pavement shoulder cracking in northern, low volume highways by incorporating TenCate Mirafi® H2Ri wicking geotextile.” Thiam gave a presentation on the research at GeoEdmonton 2018, the Canadian Geotechnical Society’s annual conference held in Edmonton, Alta. in September, as well as at the Transportation Research Board’s conference in Washington, D.C. in January and at the Transportation Association of Canada’s conference in 2017.
Over three years, the researchers conducted instrumented site monitoring, data analysis, field testing, and surveying on sections of the Campbell Highway near Watson Lake, Yukon. They concluded that shoulder cracking is caused by a combination of factors including differential compaction and differential freezing and thawing. They also concluded that the wicking geotextile reduced shoulder cracking by draining moisture effectively.
“There are many variables that cause pavement shoulder cracking,” says Thiam. “In areas where shoulder cracking was most severe, we demonstrated that at a given depth, the temperature and moisture levels of the road’s running surface are different than on the shoulder. We believe that winter road maintenance practices play a major role in these differences. We also noticed considerable differential in compaction between the road running surface and the road shoulder, which we believe is linked to the road side slope.”
The study confirmed the effectiveness of the H2Ri. “This research will provide knowledge to decision makers about solutions to mitigate pavement distress, improve bearing capacity, and decrease road maintenance costs,” says Thiam.
Other factors such as construction practices, material specifications, and location of the wicking fabric inside the road matrix should be the focus of future research.
For more information, please contact Papa-Masseck Thiam.