Study of the time-dependent thermal behavior of the multilayer asphalt concrete pavement in permafrost regions

Abstract

Asphalt concrete is one of the widespread pavement materials. The multilayer asphalt concrete pavement (MACP) has strong heat-absorption capacity. The thermal behavior of the MACP can affect the energy exchange between atmosphere and embankment, especially for the permafrost ground which is sensitive to temperature. To investigate the thermal behavior of the MACP, an in-situ experiment was performed firstly to investigate the effect of MACP on the cooling performance of an air convection embankment used in permafrost region. Subsequently, a mathematical model was developed and validated to describe the thermal behavior. Finally, series of simulations were carried out to evaluate the time dependence of the thermal behavior. The results indicate that, (1) the asphalt pavement can alter the energy exchange between permafrost foundation and atmosphere, and reduce the cooling performance of the embankment; (2) the construction interval of MACP can strengthen the convective cooling capacity and accelerate the heat dissipation of the permafrost foundation; (3) an optimized construction interval was proposed for the simulated air convection embankment to maintain its long-term stability. The study can contribute to the construction control of air convection embankment with MACP in permafrost regions.