Behaviour of asphalt mixtures containing reclaimed asphalt pavement and asphalt shingle

This paper presents the results of laboratory research on asphalt mixtures containing reclaimed asphalt pavement (RAP) and asphalt shingle, including the study of their linear viscoelastic (LVE) behaviour and fatigue characteristics. Complex modulus measurements using the tension-compression test on cylindrical specimens were conducted to determine LVE behaviour. Sinusoidal cyclic loadings with a strain amplitude of approximately 50×10−6 were applied at several temperatures (from−30°C to+40°C) and frequencies (from 0.01 to 10 Hz). In addition to axial stresses and strains, radial strains were also measured. The complex modulus E* and complex Poisson's ratio ν* were then obtained and the three-dimensional (3D) LVE behaviour (with isotropy hypothesis) was then completely described. The time–temperature superposition principle was verified with good approximation in uni-dimensional and 3D conditions for the same values of shift factor. Experimental results were modelled using the 2 springs, 2 parabolic creep elements and 1 dashpot model developed at University of Lyon/ENTPE. Fatigue properties were evaluated by tension-compression tests on cylindrical specimens using the same testing device used for complex modulus. Sinusoidal loading at 10 Hz in controlled axial strain mode was applied at 10°C. The variation of complex modulus E* and complex Poisson's ratio ν* as a function of the number of cycles was obtained. The fatigue test results were analysed using six different fatigue life criteria. The analysis of the results provided a ranking of the tested materials. The influence of RAP and asphalt shingle contents was quantified.