Asphalt Binder Modification in Flexible Pavement Using Different Amounts of Crumb Rubber

Abstract: Every year, thousands of tires made of crumb rubber are consumed as scrap. Burning this material means that more landfill space is needed, which creates a crumb rubber in PG76 performance grade and 80–100 penetration grade asphalt binder mix. Using a wet method, the asphalt binders were combined with waste crumb rubber to create a powder form 40 mesh (0.425 micron). health risk and environmental problems. The study concentrated on using crumb rubber to replace 15, 20, and 25% of the modified asphalt binder mix's total weight. The Malaysian JKR/SPJ/2008-S4 standard and the American Society for Testing and Materials (ASTM) served as the foundation for the laboratory work. Numerous tests were carried out, including pressure aging vessel, rolling thin film oven, penetration, softening point, and viscosity testing on modified asphalt binder. The outcome demonstrates a beneficial effect, with penetration decreasing as 80–100% and PG76 blend asphalt binder are partially substituted with crumb rubber. In contrast to 80–100 asphalt binder, the PG76 asphalt binder result exhibits reduced penetration in terms of stiffness throughout both short- and long-term aging. The softening point test results indicate that replacing a portion of the asphalt binder with crumb rubber raises the temperature of the PG76 and 80-100 asphalt binder mix. This is especially true after the PG76 short-term aging test (RTFOT) at 20% replacement when the temperature reached 85°C, and after the long-term aging test (PAV), when the temperature dropped to 75°C. However, resistance to increased temperature susceptibility is indicated by the partial replacement of asphalt binder by crumb rubber. According to the results of the viscosity test, the PG76 asphalt binder is more viscous than the original PG76, and the 80-100 asphalt binder replacement is made of a crumb rubber mix. For the short-term aging (RTFOT) test, the PG76 asphalt binder suggests that a crumb rubber replacement of 20% is ideal. When compared to the RTFOT test, the viscosity decreased in the long-term aging (PAV) test.