Investigating the Effect of Degree of Blending on Performance of High RAP Content Mixtures

Molecular dynamics simulation and experimental validation on the interfacial diffusion behaviors of rejuvenators in aged bitumen

“…When the diffusion time is at 10 ns, part of the rejuvenator molecules could reach the bottom of the aged bitumen layer. However, the diffusion time of 10 ns is still insufficient to form a homogenous rejuvenated bitumen, which agrees well with the previous finding that the partial blending between rejuvenator and aged bitumen was observed during the recycling of asphalt mixtures [5,20]. In addition, the micro-voids in a rejuvenator layer refer to the bitumen molecules, indicating that the interfacial diffusion phenomenon between the rejuvenator and aged bitumen molecules is mutual, which was also observed by microscopic morphologies [16,17].…”

“…Afterward, a large amount of reclaimed asphalt pavement (RAP) is fabricated [3]. Considering both economic and environmental benefits, reusing these RAP materials in new asphalt pavements is attracting extensive attention [4,5]. Nevertheless, the amount of RAP materials in new asphalt mixture is limited and controlled because incorporating RAP without using soft bitumen or recycling agent would deteriorate the cracking and moisture damage resistance of asphalt pavements [6,7].…”