From Laboratory Mixes to Full Scale Test: Rutting Evaluation of Bio-recycled Asphalt Mixes

The present paper describes the rutting behavior of innovative mixes incorporating 50% of Reclaimed Asphalt (RA) with bio-materials. They were assessed in the laboratory and in a full-scale accelerated experiment. The innovative mixes studied here contained bio-materials especially designed to help recycling by re-activating the aged binder from RA. Four mixes were evaluated: three of them are manufactured with bio-materials, (two bio-rejuvenators and one bio-binder) and one was a control mix, which was a high modulus asphalt mix (EME2). In this study, the rutting resistance of the four mixes was first evaluated in the laboratory with both European and US methods. The full-scale test was then performed in order to evaluate the rutting resistance of the bio-recycled asphalt mixes under heavy traffic (200,000 load cycles loaded at 65 kN) and compared with the control one. A simplified analysis leads to the conclusion that, with the Nantes climate, a daily traffic of 150 heavy vehicles per day applied over 20 years corresponds to approximately 200,000 heavy vehicle loads when the surface temperature exceeds 30 °C. Therefore, it can be considered that the rutting evaluation made on the carrousel represented almost 20 years of traffic during hot-day periods. The results obtained on the test track were consistent with the laboratory rutting tests showing good performance for all the mixes. The materials presenting the best performance on the test track also presented the best performance in the laboratory.