Pavement Life–Extending Potential of Geosynthetic-Reinforced Chip Seal with High-Reflectivity Aggregates

Abstract

High temperatures in asphalt pavements lead to rutting and age-related cracking. Although beneficial for reducing distresses, thicker layers are not generally used in low-volume roads because of cost restrictions. This paper presents an alternative approach in which a geosynthetic-reinforced chip seal layer with high-reflectivity aggregates is used to reduce the temperature in asphalt pavements and therefore reduce the potential of rutting and the rate of aging. If the absorption of the surface of the pavement is lowered and the conductivity of the layers is reduced, then less heat will penetrate through the depth of the pavement, and a lower pavement temperature will result. The absorption at the surface can be reduced through the use of a surface layer with greater reflectivity, and the conductivity can be reduced with the help of a layer of a material that has very low conductivity. Therefore, a composite pavement system can be used for low-volume, asphalt-surfaced roads; the system would incorporate an insulation layer and a high-reflectivity surface layer. The insulating layer will also effectively protect the surface from air and therefore significantly reduce the oxidation exposure and aging of the asphalt binder and the resultant stiffening of the asphalt mix. Analyses of modeling or simulation data and field data from a test section demonstrated a significant reduction in temperature throughout the depth of a pavement and an extension of life by three to four times.