Facile Characterization of Asphalt Modified Utilizing Thermoplastic Polymers

Various commercial thermoplastic polymers, including styrene-butadiene rubber (SBR), polyacrylonitrile (K), polystyrene (PS), polypropylene (PP), and polychloroprene (PC),are employed to modify two types of asphalt: asphalt 60/70 Suez (L) and asphalt 80/100 Alex (H). The optimal ratio of polymer additives, introduced using a hot mixing process at temperatures between 150°C and 170°C, was determined based on the measurements of penetration, softening point, penetration temperature susceptibility (PTS), and penetration index (PI) for the cooled blended formulations. For asphalt L, the ideal polymer-to-asphalt ratio was found to be 6% for SBR and PP, 9% for PS, and 12% for PC. In the case of asphalt H, the optimal ratio was 6% for SBR, 9% for PP and K, and 12% for PS and PC. Dynamic viscosity tests conducted using a rotational viscometer (RV 12) involved shearing the samples for five minutes at a high shear rate of 1198.08 s⁻¹ followed by ten minutes at a low shear rate of 149.76 s⁻¹ at temperatures ranging from 30°C to 60°C. These tests revealed that formulations LSBR and HSBR exhibited high yield stress values, suggesting promising potential for use in pavement applications. Additionally, formulations using asphalt H modified with SBR demonstrated superior tensile strength andthermal stability, maintaining performance at 250°C over a period of 150 hours. All polymer-modified asphalt samples demonstrated enhanced resistance to various application conditions compared to the unmodified base asphalt.