Thermal properties of some asphaltic concrete mixes

Abstract

To obtain an increased understanding of the energy transfer in asphaltic concrete recycling processes that use surface heat, laboratory tests were carried out on four asphaltic concrete mixes (three having limestone aggregate and one with expanded shale lightweight aggregate) to determine thermal properties. It was found that the thermal conductivity of the three limestone mixes depended on asphalt content and aggregate gradation, but that the conductivity of the lightweight aggregate mixes varied little as the asphalt content was increased from 3.5 to 6.5 percent. The specific heat and diffusivity of the mixes varied with mineralogy and gradation but changed little with asphalt content.