Use of Industrial Reclaimed Filler to Modify Asphalt Mixture and Binder Performances. Advanced rheological performance evaluation and 3D DEM Modeling of bituminous binders and mastics

The mechanical performance of an asphalt mixture is largely dependent on the properties of its constituents and by the way they reciprocally interact in the bituminous layer. In particular, the stress-strain response of the road pavements is closely related to the rheological behavior of the bituminous binder and of its interaction with the finest part of the lytic skeleton. Therefore, it is important to study in the laboratory by means of advanced rheological tests, how mastics (Bitumen-Filler Systems) and mortars (Bitumen-Filler-Sand Systems) react to dynamic loads and thermal stresses. Moreover, the understanding of the contacts mechanisms within the bitumen-filler system, through 3D micro-mechanical models, should allow for a deeper analysis of the mastic rheological behavior. Based on these considerations, in a socio-economic context in which it is necessary to reduce the environmental impact caused by the construction and maintenance of transportation infrastructures, bituminous mastics containing different reclaimed fillers from the industrial production wastes were studied. For this purpose, advanced rheological tests have been first validated and then implemented and combined with the 3D DEM models development. Results showed that the methods used to study the bituminous mastics and mortars allowed to understand the effects due to the addition of innovative and recycled fillers within the mixtures blend, highlighting as these can increase the asphalt mixture performance during its service life.