ABSTRACT
Recent researches indicate that phase separation behavior in asphalt is wax induced and the rippled phase (so-called bee structure) may consist of wax material. This study aims to investigate the wax-induced phase separation behavior and its impact on asphalt’s rheological properties. Two asphalts were blended with three kinds of commercial petroleum-derived microcrystalline waxes. In order to obtain the details of microcrystalline wax, nuclear magnetic resonance was used to investigate molecular structure of microcrystalline waxes. Phase separation behaviors of asphalts blended with microcrystalline waxes were scanned using atomic force microscopy. Fourier transform infrared results of all samples were also provided. Rotational viscosity and bending beam rheometer were employed to characterize asphalts’ rheological properties. Relationship between phase-separation behavior and macro properties is investigated by correlating atomic force microscopy result and rheological properties. The formation mechanism of bee structure is proposed.
