Studies on the Variation in Performance of Different Types of Asphalts Produced from the Same Oil Source

The 50A and 70A asphalts produced by the same oil source have great differences in macroscopic properties. However, Fourier transform infrared spectra of 50A and 70A asphalts are almost identical with no differentiation in fingerprint region which offers great difficulty in bifurcation in chemical compositions of the two types of asphalts. To cope with these deficiencies, this study is aimed to investigate the composition and micro-performance of 50A and 70A asphalts via other unequivocal techniques including elemental analysis, scanning electron microscopy, fluorescence microscopy, X-ray diffraction analysis, gel permeation chromatography and nuclear magnetic resonance spectroscopy. Through these analyses, it was found that high temperature sensitive property, i.e., low penetration index of 50A asphalt was due to its higher contents of alkane moieties. Similarly, the dynamic viscosity of 50A asphalt was much higher than that of 70A asphalt due to larger relative molecular weight, high aromatic carbon contents and more aromatic rings in the former. This study systematically explained the reasons responsible for the differences in the macroscopic phenomena of different types of asphalts produced from the same oil source, which can establish a bridge between the macro-test results and microscopic properties of asphalt and hence can best analyze asphalt produced from the same oil source resulting in collection of broader and diverse information.