Novel Application of Reclaimed Asphalt Pavement in Construction of New Cold Mix Pavements

In some regions of northwestern Pennsylvania, high-quality aggregate for use in hot mix asphalt (HMA) has been significantly depleted and is not readily available. This shortage has triggered removing high-quality coarse aggregate from reclaimed asphalt pavement (RAP) for use in HMA construction, leaving the fine millings behind. Research was conducted to seek alternatives for use of the remaining fine portion of the RAP. The suitability of using fine millings in construction of cold mix thin overlays, the binder course of new pavements and the main course in low-volume highways was evaluated through a set of laboratory experiments. A range of moisture and emulsion contents were used to prepare cold mix specimens, which were fabricated to represent thin overlays and new pavements. Indirect tensile strength was selected as the principal measure of suitability for the proposed applications. Results suggest that the cold mix thin overlays made with the fine portion of RAP, as well as thicker layers made with a blend of the fine portion of RAP and virgin coarse aggregates, can be effectively used for rehabilitation or new construction. Raveling tests were also conducted, and it was found that the cold mixes with RAP can perform satisfactorily under repetitive traffic loading. Field studies are required to verify the findings from this research.