ABSTRACT
Multi-recycling of Reclaimed Asphalt Pavement (RAP) in bituminous mixtures is a relatively new procedure of growing interest for the research community. The aim of this paper is to show the influence of several RAP recycling cycles on thermo-mechanical properties of bituminous mixtures.
Three hot bituminous mixtures were studied. The first mixture, considered as reference, was fabricated without RAP, using a 35/50 pen grade binder. The second one contains 40% of RAP and was used, after aging procedure, as RAP for the third mixture. Therefore, this last mixture, containing 40% of the “aged” second one, contains only 16% of the original RAP, subjected to two recycling cycles. A 50/70 pen grade bitumen was used as fresh binder for the two mixtures containing RAP.
Complex modulus tests were performed to determine the Linear Viscoelastic (LVE) properties of all mixtures. 2S2P1D (2 Springs, 2 Parabolic Elements and 1 Dashpot) model was used to fit all experimental data. The evolution of LVE properties and 2S2P1D model parameters were analysed as a function of the different composition of mixtures. Similar results were obtained for the two mixtures containing RAP, regardless of the number of recycling cycles.
