modification used the additive such as organo- metallic compounds. It used the
chemical agent as additive to modify the characteristic of pure bitumen. Due to
vary complex structure of bitumen chemical modification of bitumen have not
been commercialized as physical modification because of Corrosion,
side effect and malodor which are problematic. Chemical
modification of bitumen is another way toactive oligomer, a short chain polymer.Chemical modification improves stiffness, blown bitumen are the best alternatives for this purpose. Analysis of the modified bitumen microstructure shows that polyphosphoric acid acts as a de-agglomerant of asphaltenes; a fraction of added acid reacts with bitumen according to the basic site of asphalten itself. In fact, the results indicated a chemical modification of the base bitumen.Penetration grades can be modified by this method. AASHTO and ASTM are common test improve asphalt binders properties:
one of the modifier could be polyphosphoric acid. PPA is a methods for
chemically modified bitumen.