Study On Compatibility Of SBS Modified Karamay Asphalt

SBS modified asphalt has been widely used for the good performance at work. But there are apparent differences exist in several aspects of properties, such as composition, structure, molecular weight, because of the variety of petroleum asphalt resource, the complexity of composition and the specialty of SBS. Therefore, the compatibility of SBS modified asphalt in the production and store process has become an important issue needed to be researched first.In the thesis, the factors affecting the compatibility have been researched systematically from four main categories in order to reveal the mechanism for compatibility of SBS modified asphalt.The effect of style, structure and S/B ratio of SBS on the compatibility of modified asphalt has been respectively studied by fluorescence microscope, infrared spectrometer and thermal storage test. The KL-A was chosen as the basic asphalt. The results showed that the star-style SBS had better performance than linear one. The modified asphalt was better when S/B ratio is 30/70 rather than 40/60. The compatibility of modified asphalt was relatively good until the blending amount of SBS was more than 3% and that tended to be worse as the rising mount of SBS, so did the storage stability.The elements, composition, molecular weight and colloidal stability of basic asphalt have been analyzed. The results of fluorescence microscope, thermal storage test and composition analysis have been used to research the effect of composition of asphalt on the compatibility. It indicated that the asphalt with high amount of aromatics, S, N and high polarity could be favorable for the promotion of compatibility. The asphalt with solubility parameter that is close to that of SBS would have the same effect.The impact of shear temperature, shear time, developmental temperature and time on the compatibility of SBS modified asphalt has also been researched by orthogonal experimental. It demonstrated that the rising temperature/time of shear could benefit the swelling and dispersion of SBS in asphalt under some constant rate of shear, which meant the increasing compatibility. The developmental temperature and time were necessary, but had relatively small influence on the modified asphalt.The addition of compatilizer and stabilizer in the preparation of modified asphalt could increase the compatibility effectively. The systematical research regarding the effect of compatilizer and stabilizer with different composition and doses was discussed at the last part of thesis. It showed that compatilizer with high amount of aromatics promoted the swelling and dispersion effect of SBS. The compatibility has been strongly affected by the variation of stabilizer type. The doses of stabilizer could have impact on the improvement of compatibility only if it reached a defined amount.