Road performances of mesoporous nano-silica modified asphalt binders

The objective of this paper was to find new modifier to improve the aging resistance and low temperature cracking resistance of asphalt. To investigate the aging resistance of modified asphalt binders, mesoporous nano-silica (doping Ti⁴⁺) was used as a asphalt modifier. Some physical properties including penetration, ductility, and softening point of asphalt were analyzed with RTFO (Rotating thin film oven) aging and ultraviolet aging. Moreover, the performances of high and low temperature of modified asphalt binders with pressure aging were tested by dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test. These results showed that the penetration decreased, low temperature ductility, and softening point increased when adding mesoporous nano-silica to base asphalt. After ultraviolet radiation aging, the penetration loss and ductility loss of modified asphalt decreased than that of original asphalt, the increase of softening point was also significantly reduced than that of base asphalt. Furthermore, The test results of DSR and BBR showed that the G*sinδ and creep modulus‘s’ of pressure aged asphalt decreased, but the creep rate ‘m’ increased. It can be concluded that the aging resistance and cracking resistance of modified asphalt are improved by adding mesoporous nano-silica, especially the doping of Ti⁴⁺ could improve the aging resistance obviously.