Abstract:
Based on the dynamic shear rheological test (DSR), the high temperature performance of three kinds of polymer modified asphalt before and after aging:polyphosphoric acid(PPA)modified asphalt, styrene butadiene styrene block copolymer(SBS)modified asphalt and SBS-PPA modified asphalt were analyzed. Results shows that: Under different temperatures and different aging, compared with SBS modified asphalt, the improvement of rheological properties of asphalt at high temperature was more prominent with PPA modifier, the viscosity of asphalt decreases and the elastic component increases. PPA was added in the SBS modified asphalt can obviously improve the elasticity of modified asphalt and reduce its viscosity. The high temperature performance of SBS-PPA modified asphalt is better than that of SBS modified asphalt. Under the long-term aging, the temperature translation point of PPA and SBS-PPA modified asphalt by the storage modulus
G' dominant role into the loss modulus
G" dominant role become higher, the temperature translation point:PPA >SBS-PPA >>SBS. For SBS modified asphalt, the effect of temperature and frequency on
G* and
δ are greater than that of aging, but the PPA and SBS-PPA modified asphalt are greatly influenced by aging. As the aging degree of deepening, can the PPA and SBS-PPA modified asphalt maintain a certain degree of flexible to resist deformation in relatively wide temperature and frequency range. PPA modified asphalt before and after aging under different temperatures and frequency have a higher
G*/sin
δ, and the
G*/sin
δ increases most after aging, high temperature anti rutting ability becomes stronger, followed by SBS-PPA modified asphalt.