Multi-modified asphalt with polyphosphoric acid/rock asphalt as additives

Abstract This research focused on the preparation of multi-modified asphalt with a composite of polyphosphoric acid (PPA) and Qingchuan rock asphalt (QRA) as modifiers. The study examined the effects of varying amounts of PPA on asphalt properties and assessed how the modifiers affected the road properties of the asphalt mixture, including water stability and high-temperature stability. Findings revealed that the optimal PPA content was 0.75%, resulting in an increase in residual stability of the modified asphalt mixture from 0.8 to 0.92 and an increase in dynamic stability (DS) from 898 times/mm to 3068 times/mm. The modified asphalt mixture blended with PPA and QRA demonstrated significant enhancements in high-temperature stability and water-damage resistance.