LAUSR

The low-temperature crack resistance of recycled asphalt has an important influence on the road performance of its mixture, and the existing study and evaluation of low-temperature performance of rejuvenated asphalt mostly adopt the method of laboratory test. To avoid the one-sided evaluation of the low-temperature performance of rejuvenated asphalt by bending beam creep stiffness test (BBR), based on the viscoelastic rheological method, Burgers model was built. The rheological indexes, including creep stiffness, creep rate, relaxation time, dissipated energy ratio and creep compliance derivative, were used to compare and analyze the low-temperature crack resistance of the original asphalt, wood tar-based rejuvenated asphalt and RA-102 rejuvenated asphalt under different low-temperature conditions. Combined with the results of component analysis, the correlation between rheological parameters and test results was established by gray correlation analysis, and the rejuvenation mechanism of low-temperature performance of wood tar-based rejuvenated asphalt was expounded. The results show that wood tar-based rejuvenator can significantly improve the low-temperature crack resistance of aged asphalt, and Burgers model can better reflect the low-temperature creep and stress relaxation characteristics of rejuvenated asphalt. Wood tar-based rejuvenator can obviously improve the relaxation property and dissipation energy ratio of aged asphalt, 10 and 12 wt% wood tar-based rejuvenated asphalt has good creep deformation ability at low temperature, which can relax the deformation caused by temperature stress in time, avoid the low-temperature cracking caused by stress concentration, thus has good low-temperature crack resistance.