Experimental investigation on fatigue properties of asphalt mixtures with high content of RAP and recycled plastics

The experimental study described in the paper explored the synergistic effects of Reclaimed Asphalt Pavements (RAP) and a polymeric compound derived from recycled plastics on fatigue properties of dense-graded asphalt mixtures. The investigated mixtures were prepared in the laboratory by combining 50% of RAP with different dosages of the polymeric compound. A control mixture containing a highly SBS-modified binder was also prepared and tested for comparison purposes. The fatigue properties of mixtures were evaluated by means of flexural test in the four-point bending configuration under oscillatory loading. The tests were conducted in both controlled-stress and controlled-strain loading modes to understand the response of materials under different critical loading conditions in actual pavement structure. The experimental results indicated that the use of high percentages of RAP combined with the use of recycled plastics resulted in good fatigue performance of the mixture. The experimental data also indicated that recycled plastics at higher dosage used in this study yielded fatigue performance comparable or even slightly higher to that obtained with the use of control SBS-modified binder.