Evaluation of high temperature rheological performance of polyphosphoric acid-SBS and polyphosphoric acid-crumb rubber modified asphalt

This study explores the effects of polyphosphoric acid (PPA) on rheological performance styrene butadiene (SBS) and crumb rubber (CR) modified asphalt binders at high temperatures. Four PPA concentrations were selected: 0.4%, 0.8%, 1.2%, 1.6% by weight virgin asphalt, one SBS binder with 5% was used as a reference binder. Laboratory tests performed to simulate short-term long-term aging. Temperature sweep, frequency multiple stress creep recovery (MSCR) repeated (RCR) also conducted investigate properties (i.e., PPA-SBS, PPA-CR modified). Fourier transform infrared spectroscopy (FTIR) test chemical reaction modifiers in asphalt. Results showed that improved asphalt’s resistance permanent deformation enhanced their elastic behavior. Moreover, results rutting factor (G*/sinδ), complex modulus (G*), zero shear viscosity (ZSV), percentage (R), non-recoverable compliance (Jnr) viscous stiffness (Gv) suggested PPA-SBS had best modification effects, followed PPA-CR. Besides, viscosity-temperature susceptibility (VTS) indicated additives decreased temperature composite binders. good anti-aging behavior when content no <0.8% Additionally, CR-modified exhibited most aging loading resistance.