Simulation and Characterization of Asphalt Pavement Temperatures

This report summarizes the results of an effort to characterize pavement temperature that includes analysis of measured asphalt temperature data from the MnROAD facility and simulations of pavement temperature using a heat transfer model. The measured pavement temperatures are characterized at daily and seasonal time scales, including daily extreme temperatures and temperature gradients, diurnal cycling, and seasonal variations. A one-dimensional finite difference model is used to simulate pavement temperature based on climate parameters such as air temperature, solar radiation, and wind velocity. The temperature simulations provide more detailed information on temperature gradients in the pavement and on the surface heat transfer components than the measurements, and also help to evaluate the quality of the pavement temperature and climate measurements. Overall, the pavement temperature model is able to simulate asphalt temperature to within a 1 to 2°C mean error, but with higher error for winter conditions due to intermittent snow/ice cover and freeze-thaw processes. The pavement temperature simulations are useful to identify the processes and weather conditions that produce the extreme changes in pavement, such as rapid cooling during precipitation events. The pavement temperature model was also able to simulate pavement temperatures at RWIS sites, and therefore could provide a means to check the quality of RWIS climate and pavement temperature data.