A numerical approach to evaluate the risk of differential surface icing on pavements with insulated sections

This paper presents the results of a numerical study on the differential icing risk at the surface of pavements with insulated sections in the Province of Quebec, Canada. Differential icing situations occur when slippery conditions form on the surface of insulated pavement sections while adjacent conventional pavement sections maintain dry surface conditions. A heat transfer model that considers the climate conditions and the pavement properties is used to compute the surface temperature of conventional and insulated pavements. Variations of climate conditions on daily cycles are obtained from a new ideal climate model developed on the basis of 30-year period monthly data of solar radiation, air temperature, wind speed and cloud cover. It was established that the period with the highest icing risk on all pavements (insulated or not) occurs during the late Fall season. However, as soon as the frost front reaches the insulating layer, the icing risks on insulated pavement sections increase drastically. In the Province of Quebec, the current insulated pavement design method prevents most of the differential icing situations only for the warmest regions of the Province. Future design method will have to relate the thickness of the granular layer placed atop of the insulating layer to mean climate conditions and pavement properties.