Study of High-Temperature Rheological Properties of Emulsified Asphalt Residues

The residue of emulsified asphalt is its final state when it becomes part of an asphalt mixture. Therefore, the mechanical properties of the residue have a significant impact on the performance of emulsified asphalt mixtures. Dynamic shear rheological tests and fluorescence microscopy were conducted to explore the effects of emulsification and aging on the rheological properties and micro-morphology of emulsified asphalt residue. The results of both the temperature sweep and multiple stress creep recovery tests indicated that the emulsification of the asphalt had different effects on the rheological properties of the base asphalt and the styrene-butadiene-styrene (SBS)-modified asphalt. For the base asphalt, emulsification increases the complex shear modulus by about 5% and reduces irrecoverable creep flexibility by 30%. However, the physical grinding effect of the colloid mill during the emulsification process could destroy the internal spatial network structure of SBS, leading to a reduction in the complex shear modulus by about 5% and a 10% increase in irrecoverable creep flexibility. This phenomenon is similar to the aging of SBS-modified asphalt, which, in turn, leads to a decline in the performance of emulsified SBS-modified asphalt residues.