Evaluation of heated reclaimed asphalt pavement material and wax-modified asphalt for use in recycled hot-mix asphalt

This study was performed to evaluate the use of heated-reclaimed asphalt pavement materials with emulsion and the use of hot-mix asphalt with wax (Sasobit) as base course materials. Mixes with lower-than-optimum and optimum emulsion content, as well as with heated-reclaimed asphalt pavement material and optimum emulsion content, were made; in addition, mixes with conventional asphalt binder and those with asphalt binder and Sasobit were produced at relatively lower temperatures. These mixes were tested for workability, and all but one were used for preparation of approximately 0.9- x 0.9- x 0.125-m slabs. The rates of densification during the compaction of these slabs were compared. Samples cored from the slabs were tested for stiffness and for dry and retained tensile strengths. The results showed that heating of reclaimed asphalt pavement material can improve the dispersion as well as the densification significantly. The use of asphalt binder was found to improve strength and stiffness, and the use of Sasobit helped to achieve almost similar workabilities and compactibilities at a lower temperature compared with those of hot-mix asphalt with neat asphalt binder. No significant difference was found between the modulus of the Sasobit and hot-mix asphalt samples. The dispersion of asphalt binder seemed to improve with the use of Sasobit at a lower mixing temperature. A field project is recommended for evaluating performance of emulsion mixes with heated reclaimed asphalt pavement materials and asphalt binder mixes with Sasobit.