Feasibility of the Multi-recycling of Bituminous Wearing Courses Through the Use of Different Rejuvenators

The maintenance and rehabilitation of road pavements consume high annual budgets from road administrations, are associated with a huge production of waste, and consequently a large use of natural resources. In this way, the multi-recycling of reclaimed asphalt pavement (RAP) presents itself as a solution to part of the problem, thus avoiding its classification as waste and consequently landfill.It is necessary to use rejuvenators throughout the successive recycling cycles to recover the properties of the RAP’s bitumen fraction, so if different rejuvenators are used in successive recycling cycles, their interaction must be evaluated. To evaluate the interaction between two rejuvenators of different origins considering two recycling cycles in RAP mixtures with high incorporation rates (75%) for wearing courses, laboratory tests were carried out to characterise the rejuvenated bitumen blends, and the bituminous mixtures regarding the mechanical properties, surface characteristics and volumetric properties.The results were compared with a previous case study where were evaluated three AC 14 surf 35/50 mixtures: one with virgin materials, and two with 75% RAP incorporation recycled one and two times with the use of a rejuvenator. Therefore, the interaction between two different rejuvenators, from similar samples, in the same recycling cycle, did not present significative variations in the tests and characteristics of the RAP, demonstrating good compatibility between the rejuvenators.