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

Abstract

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.