Asphalt cement will not last long as the world encounters a diminishment in crude oil. Novel resources can contribute to replacing asphalt with the sustainable, flexible pavement. This study presented guayule resin (guayule) as an innovative bio-based asphalt alternative. Ground tire rubber was used as an asphalt enhancer. To judge the guayule\u27s contribution, guayule-based binders were investigated and compared to control asphalt and asphalt-rubber binders. Binders were assessed according to comprehensive Superpave criteria and advanced rheological tests. Component analysis was performed to link the microscale level with the macroscale level. To validate the novel binder, satisfying mix performance tests were conducted. The outcomes revealed a lower viscosity for guayule than asphalt, indicating savings in plant energy consumption. Guayule had similarities with asphalt in component composition and rheological behavior with temperature susceptibility. Asphalt-guayule interaction yielded a physical blending with no chemical reaction. Rubber enhanced guayule at high temperatures, but not as much as asphalt, as proven by polymeric component migration through liquid binder due to depolymerization occurred. However, because of strong oxidation bonding chains attributed to guayule, the oxidative aging negatively affected the guayule-based binder’s long-term distresses. Validation by mix performance assessment revealed that guayule supported mix stability against moisture (particularly at lower air contents), rutting, and fatigue cracking, but had low thermal fracture resistance. In a nutshell, guayule had potential to replace conventional asphalt to compensate or surpass the asphalt performance required partially or even entirely at specific grades --Abstract, page iii
