Strategies for Reduced Cooling Time of Asphalt for Airfield Pavement Overlay

Reducing the cooling period of newly laid asphalt overlays could help airport authorities to quickly open remediated pavements to traffic. This paper reviews four strategies for a reduced cooling period, prior to trafficking, of newly-placed asphalt overlays: (1) defining and selecting the warmest permissible asphalt temperature at opening to traffic, (2) reducing the cooling time by using warm mix asphalt (WMA), (3) increasing the cooling rate of asphalt by using high thermal conductivity material, and (4) decreasing the pavement temperature by spraying water onto the freshly paved asphalt. A one-dimensional (1D) heat-transfer model using a finite element (FE) solution is developed as a function of weather conditions to simulate the effect of each strategy on asphalt cooling time. The analysis shows that each strategy significantly contributes to the rapid cooling of newly laid asphalt. However, there are some concerns over the performance of the pavements when some strategies are adopted.