Evaluation of Mechanical Performance in Cold Mix Asphalt Mixtures: A Comparison of Various Recycling Techniques

Cold-mix asphalt (CMA) is generally characterized as an asphalt mixture produced at an ambient temperature either in a central mixing plant or in place on the road. Cold central plant recycling (CCPR) and full-depth reclamation (FDR) are frequent cold recycling techniques for rehabilitating deteriorated pavement. This study investigated the mechanical performance of various CMA mixtures using both virgin and recycled aggregates. The dynamic modulus, the disk-shaped compact tension (DCT), and the Hamburg wheel-track tests were used to study the mixtures’ viscoelastic behavior, cracking resistance, and rutting resistance. CCPR and FDR mixtures with 2.5% emulsified asphalt and 2.5% water (by total mixture mass) using 100% reclaimed asphalt pavement (RAP) exhibited the best results of the cold-recycled mixtures tested. While CMA mixtures containing partially virgin aggregate tend to show high air voids contents, contributing to their inferior performance compared to hot-mix asphalt (HMA) mixtures and the CCPR and FDR mixtures. CMA mixtures fabricated with virgin materials exhibited poorer rutting performance, while CCPR and FDR had better rutting resistance but were still inferior to HMA mixture rutting performance. CCPR showed better mechanical performance than the FDR.