The bitumen properties directly correlate to great resistance to temperature and traffic load, which represent the main criteria for prolonging the life of a pavement. Waste materials are taken into consideration as possible candidates for expanding pavement lifespan in order to comply with those performance standards. Consequently, to meet the prerequisite for sustainable building methods, this research focused on using crumb rubber (250 µm or less) of waste scrap tires as a modifier to the bitumen asphalt. This crumb rubber is added with a percentage of 15% of bitumen pen 40/50 and mixed mechanically with the shear mixture for 0.5 h at 180 οC to produce rubberized asphalt. To investigate the physical, rheological, and mechanical properties of modified bitumen, penetration, softening point, ductility, and viscosity experiments were conducted in addition to empirically determining temperature susceptibility and bitumen stiffness. Results showed that crumb rubber lowered the penetration by 15% in comparison to the reference asphalt bitumen while softening point increased by 10%. Furthermore, ductility decreased by 26%. Moreover, rotational viscosity increased by 72% and 155% at 135 οC and 165 οC, respectively. Modified asphalt shows less temperature susceptibility, where the penetration index changes from −0.91 to −0.07 and penetration viscosity number changes from −0.33 to 0.22, and stiffness improves by 60% for rubberized bitumen compared to the control asphalt bitumen.