Abstract
The effects of short and long-term thermo-oxidative aging on stripping resistance, rut depth, stiffness modulus, fracture and fatigue resistances of asphalt concretes have been assessed. A modified RILEM thermo-oxidative aging procedure on loose asphalt mixtures has been used to evaluate the gradual evolution of these properties with the aging duration. Two short-term aging durations (4 and 8 hours at 135C) and three long-term thermo-oxidative aging durations (3, 6 and 9 days at 85
C) and a reference mixture (0 day aging) have been considered to this end. The impact of long-term thermo-oxidative aging on the chemo-rheological properties of recovered asphalt binders have been investigated. At the binder scale, the results show an increase in the Fraass temperature, the softening point, the shear modulus
, the aging index (AI=
+
) and a decrease in the penetration grade with the aging duration. Some correlations between the viscoelastic transition parameters (
,
and
) of the recovered asphalt binders and the aging index have been established. At the mixture scale, the results show that the stiffness modulus (
) increases with the aging duration, while the index of fracture resistance (IFR), the stripping resistance (
), the rut depth (P) and the fatigue deformation (
) decrease with the aging duration. Finally, some correlations between the aging index and the rheological and the mechanical properties of binders and concretes (
,
, P, IFR,
) have been proposed.
Acknowledgments
The authors would like to thank Michel Liffraud at Cerema Toulouse, for its generous help in performing a part of the DSR tests on the asphalt binders.
Disclosure statement
No potential conflict of interest was reported by the author(s).