Changes in Asphalt Binder Grade Due to Climate Change in Canada

In recent years, average temperatures in Canada have been continuously increasing, owing to changes in the global climate. This can be attributed to a surge in the concentration of greenhouse gases in the atmosphere. Climate scientists predict the trend to further aggravate in the near future. Pavement performance models show that changing climate will result in accelerated pavement deterioration. To mitigate pavement deterioration, various adaptation strategies have been suggested in the recent literature. One of these adaptation strategies is upgrading the superpave asphalt binder grade. It is well known that asphalt binder is highly sensitive to climate factors such as temperature and percent sunshine. Hence, reviewing asphalt binder grade is a vital step and that can help decelerate pavement deterioration. The goal of this work is to determine new asphalt binder grades in Canada based on the projected climate data. To achieve this goal, the analysis was carried out in four phases.

In the first phase, statistically downscaled climate change models were gathered from the Climate Change model database. Then in the second phase, hourly temperatures were estimated using existing hourly data and state of the art estimation models for each day throughout the design period. Later in the third phase, using the estimated hourly temperature, average seven-day maximum pavement temperature and minimum pavement temperature are determined. Lastly, high-temperature grade (XX) and low temperature grade (YY) of an asphalt binder (PG XX – YY) are estimated using the average seven-day maximum and minimum pavement temperature respectively and tabulated in an easy-to-use format for application by the transportation agencies in Canada. Results reiterate the necessity of upgrading the asphalt binder grade in various provinces of Canada.