Seasonal Response and Damage Evaluation of Pavements Comprised of Insulation Layers.

A well-known strategy for minimizing the negative effects of prolonged low temperatures on frost-susceptible subgrade is using insulation layers. Insulation layers help to mitigate the formation of ice lenses and frost heave in the subgrade. This paper evaluates the effect of using bottom ash (B.Ash), as well as polystyrene boards, on the seasonal response of the pavement at the University of Alberta's Integrated Road Research Facility (IRRF) in Edmonton, Canada. Over the course of one year of data monitoring, from July 2014 until July 2015, different seasons (non-freeze-thaw, frozen, and recovering) were distinguished using the temperature and moisture data received from time domain reflectometers (TDRs) and thermistors installed across the pavement depth. Then, the time history data collected from falling-weight deflectometer (FWD) tests was used to identify the characteristic response of different sections. Results revealed that the B.Ash section performed similarly to the control section (CS) in terms of viscoelastic behavior, and the B.Ash perfor med considerably better than the CS in terms of the risk of fatigue cracking. However, the polystyrene sections were more prone to damages during the summer when the hot mix asphalt (HMA) temperature was more than 25°C. [ABSTRACT FROM AUTHOR]