On the Optimization of the Aggregate Packing Characteristics for the Design of High-Performance Asphalt Concretes

ABSTRACT In the framework of a partnership between the European EIFFAGE Travaux Publics Group and the Ecole de Technologie Supérieure (ETS) from Montreal (Québec), some basic concepts associated with granular combinations and aggregate packing characteristics enabled the development and design of high-performance self-blocking asphalt concretes. The aggregate packing methods first developed in the field of high-performance cement concretes were successfully transposed to the field of asphalt concretes. Laboratory assessment in both laboratories of the ETS and EIFFAGE Travaux Publics consisted in the evaluation of the compactin g ability using the French gyratory shear compactor (GSC), the resistance to moisture using the so-called Duriez test, the resistance to rutting thanks to the French wheel tracking tester at 60°C, the secant stiffness modulus at 15°C and the fatigue resistance at 10°C. The paper concludes that the grading analysis concepts allow the design engineer new insights into the structure of aggregates. The proposed principles can be used to develop more specific guidelines for aggregate structure selection of high-performance asphalt concretes.