Catalogue of Flexible Pavements Incorporating Reclaimed Asphalt Pavement (RAP) in Unbound Granular Layers of Low-Volume Roads

The maintenance and rehabilitation of flexible pavements generates an appreciable volume of waste from the reclaimed asphalt pavement (RAP). One of the processes for the RAP valorization is the transformation into recycled aggregates to be reintegrated in the pavement life cycle, towards a circular economy model. Unbound granular layers of flexible pavements are a field of application of these recycled aggregates. The objective of the paper is to present a catalogue of flexible pavements incorporating RAP in unbound granular layers, developed in Portugal for low volume roads. Beyond the catalogue, the paper describes the research work developed to demonstrate the mechanical and environmental performances of the proposed pavement structures. In laboratory, cyclic triaxial tests and leaching tests were conducted in addition to current geometric, physical, and mechanical tests. Load tests were carried out on experimental full-scale pavements to validate the mechanical behavior of RAP mixtures in real conditions of application. The paper introduces traffic, materials, and subgrade conditions that supported the application of the catalogue. The catalogue aims to contribute for the implementation of sustainable pavement solutions in road construction.