Balanced Mix Design for RAP-Rich High-Modulus Asphalt Concrete: Comparative Analysis of Rutting, Intermediate- and Low-Temperature Cracking

The balanced mix design (BMD) framework allows engineers to incorporate high reclaimed asphalt pavement (RAP) contents by using performance tests that capture multiple distress modes. This study developed a high-performance asphalt concrete (HPAC) inspired by the French High Modulus Asphalt (EME) concept, containing 50 % RAP within a performance-based BMD framework. Unlike EME, which uses hard binders, the HPAC used a conventional PG 64-22 binder together with RAP sourced near Edmonton. Three RAP binder activation levels, 60 %, 80 %, and 100 %, were examined to reflect partial blending behavior. Performance tests included Hamburg Wheel-Tracking (rutting and moisture resistance), IDEAL-CT (cracking), and DCT (low-temperature fracture). The 80 % activation produced the most balanced performance, while 60 % caused rutting and 100 % reduced cracking tolerance. Overall, a 50 % RAP-HPAC met stiffness and durability targets while maintaining balanced performance, offering a practical and sustainable solution for cold-region pavements.