Design and Construction of Foamed Recycled Asphalt Pavement Base Materials

Utilization of existing recyclable materials has always been a key to more efficient and economical highway construction. The use of foamed asphalt technique to stabilized recycled asphalt pavement (RAP) is one strategy for an efficient use of salvage construction materials. The main objective of this study is to investigate the potential use of foamed asphalt treated RAP as a base course material in lieu of a crushed lime stone base underneath a concrete pavement layer. Test sections were constructed at US Highway 190 near Baton Rouge, Louisiana and used for field evaluation of the foamed asphalt RAP base. This paper presents the laboratory mixture design of the foamed asphalt RAP, the construction of experimental base section, and the field evaluation of the stiffness of the foamed asphalt RAP base layers using different in-situ testing devices. Preliminary results of both laboratory and field tests showed that the use of foamed asphalt treated RAP mixtures is very promising and can be used as an alternative to traditional used lime-stone base underneath of a concrete pavement layer.