The rubberized asphalt binder properties are affected by crumb rubber (CR) distribution through matrix. The distribution could be
enhanced by chemically modification for CR. Silicone oil, maleic anhydride and dispersing agent were used as chemicals to modify
CR by10 per hundred weight of asphalt (pha) with different doses and physical, mechanical and morphology properties of
rubberized asphalt binder were examined. The chemicals led to increase penetration and softening point values till a certain
chemical dose then decreased, and the tensile strength and elongation at break values was also affected by dose of chemical.
Scanning electron microscopy (SEM) illustrated that silicone oil and dispersing agent caused better distribution of CR, while maleic
anhydride affected CR to be cross linked with asphalt matrix. The best dose of silicone oil and dispersing agent was 1.5 per hundred
weight of rubber (phr), while maleic anhydride was 1.0 to 1.5 phr.