Modeling the evolution of winter damage in an asphalt concrete microstructure

Winter damage in asphalt pavements is a complex phenomenon which may cause pothole formation, dislodging of stones and structural layer separation. In order to reduce the winter damage, knowledge about the process in both the pavement and on a microstructural level is required. This paper focuses on modeling the process of damage evolution on a microstructural level in order to identify and understand the different phenomena influencing the degradation process. In this paper the evolution of winter damage in an asphalt concrete microstructure was modeled throughout the course of two winter seasons. The simulations include freezing and thawing cycles as well as additional damage originating from snow plows, both based on real weather data from Luleå in the north of Sweden. The results show a large increase of damage in both the mastic and the aggregate-mastic interface, and thereby also vertical displacement of the top surface, after the first freeze-thaw cycle. During the following freeze-thaw cycles the mastic damage continuous to increase but with a decreasing rate while the damage in the aggregate-mastic interface is only affected by the manually added damage from the snow plow. These results indicate a need to include the growth of -and emergence of new air voids in the model as well as an investigation of the actual behavior and influence of the damage evolution in the interface regions.
QC 20190513