李李 LI Bin( ): Ph D Candidate;Abstract: Effect of organo-montmorillonite (OMMT) on the morphology and aging properties of various bitumens was studied. The morphology of the binders was characterized by atomic force microscopy (AFM). The influence of OMMT on physical properties of the binders before and after long-term aging and ultraviolet (UV) aging was investigated. It was observed that the effect of OMMT on the morphology and aging properties of bitumens depended on the base bitumen. In one case, OMMT affected the dispersed phase in bitumen. In the other case, OMMT affected the bitumen matrix. In both cases, OMMT caused stiffening of the modified phase. Compared with modification of the dispersed phase, modification of the matrix phase showed an obvious improvement on the physical properties as well as the better UV aging properties of bitumens, which was opposite to the long-term aging result.