A review of fatigue damage in bituminous mixtures: Understanding the phenomenon from a new perspective

• Innovative fatigue phenomenon approach to study bituminous materials.
• Molecular mobility could play a significant role in the appearance of fatigue damage in bituminous materials.
• Various materials under different test conditions were performed through UGR-FACT.

Fatigue cracking constitutes one of the main distresses responsible for the decline in the service life of asphalt pavements. The study of fatigue phenomena is therefore a field of research that has become crucially important for enhancing the durability of these structures. In spite of the advances achieved in the understanding of the fatigue phenomenon in bituminous materials, there remain some questions that are in need of further research. Firstly, the majority of studies do not consider the influence that permanent deformations can exert on the mechanical response of materials. Secondly, reversible phenomena that co-exist with damage during the development of fatigue processes make it difficult to accurately measure the latter. Further, given that the fatigue phenomenon has both global and local effects that cannot be dissociated, the analysis and failure criteria used could lead to non-homogenous results and incorrect fatigue life predictions. This research therefore constitutes a deeper examination of these issues and proposes a new approach that allows for a global analysis of the fatigue phenomenon. This approach has been tested through the study of various types of materials under different test conditions using the UGR-FACT device. Results have shown that using this approach it is possible to distinguish between the different phenomena that appear during cyclic loading and to establish a homogenous failure criterion. In addition, it has been demonstrated that molecular mobility could play a significant role in the appearance of fatigue damage in bituminous materials.