he effects of styrene butadiene rubber (SBR) on softening point, penetration and ductility of C₉ petroleum resin modified asphalt were studied. The mechanism for SBR- C₉ petroleum resin-modified asphalt was also discussed. The results show that SBR can effectively improve the softening point of C₉ petroleum resin-modified asphalt. When introducing 4.0% mass fraction of SBR, the performance of modified asphalt could meet the required standard of JTJ036-98. The four components (saturation, aromatic, resin and asphaltene) analytical results indicate that the aromatics content of the modified asphalt system can be increased after adding C₉ petroleum, thus the swelling and adsorption of SBR in the C₉ petroleum resin modified asphalt can be promoted. Electron microscopy result demonstrates that, when the SBR content is 5.0%, the C₉ petroleum resin modified asphalt shows good compatibility, stability, and numerous crazes. A three pitch stable polymer network structure might be formed for the SBR, C₉ petroleum resin, and asphalt system.

C9 petroleum resin was used to modify the Liaohe 90# asphalt. The influence of the amount of C9 petroleum resin on the matrix asphalt performance has been studied ,and the modified asphalt structure has been analyzed by the scanning electron microscope (SEM). The experimental results show that, with the addition of C9 petroleum resins, the modified asphalt softening point was gradually increased, whereas the penetration was gradually decreased. The SEM analysis indicated a good compatibility of C9 petroleum resin and matrix asphal when the dosage of C9 petroleum resin was 4%, while the segregation phenomenon occured if the amount of C9 petroleum resin increased to 5%.