Rheological Characterization of the Fatigue Resistance of Asphalt Binders

Fatigue cracking of bituminous layers is the most common mode of failure for flexible pavements. This distress is mainly related to the rheological properties of asphalt binders. The purpose of this work is to investigate the fatigue behaviour of asphalt binders using cyclic shear tests. Tests are carried out both in the stress and strain controlled mode, using a dynamic shear rheometer (DSR). The study focuses on the evaluation of different binders, and also considers the influence of temperature. Results show that the complex modulus and its fundamental components are useful parameters to understand the damage evolution in the material. Data elaboration allows fatigue characterization by means of conventional fatigue curves based on stiffness loss and dissipated energy. Through the analysis of these curves it is also possible to show and quantify the increasing fatigue resistance due to the addition of polymers in the binder.