Critical assessment of new polymer-modified bitumen for porous asphalt mixtures

New experimental polymer-modified bitumen with a high-vinyl content polymer was fabricated for porous asphalt (PA) mixtures. The bitumen with maximum stability was achieved using storage stability, gelation criteria and physical bitumen tests. A dynamic shear rheometer was used to compare the complex modulus, number of fatigue cycles, yield stress, and non-recoverable creep compliance of the experimental bitumen with a reference virgin bitumen 50/70 and a PMB 45/80-65 binder. PA mixtures were also designed to analyze the abrasion resistance and binder drainage characteristics. It was concluded that the experimental bitumen with 4.5% polymer content showed higher elastic response, better fatigue resistance, and improved rutting behavior than the reference PMB. PA mixtures with the new experimental bitumen exhibited higher abrasion resistance, but underwent higher binder drainage, which was addressed by the incorporation of aramid pulp and glass-hybrid fibers.