Mean damage parameter for the characterization of fatigue cracking behavior in bituminous mixes

The optimization of the laboratory mix design is crucial to improve the performance of the asphalt mixes during its service life. For this purpose it is necessary the use of tools that can efficiently measure the mechanical response of these materials. Fatigue cracking is one the main distresses that occurs in pavements around the world. During the laboratory tests, this phenomenon is difficult to characterize because of its heterogeneous nature (disperse in the three dimensions and random). In order to improve the characterization of the fatigue cracking behavior of asphalt mixes, this research proposes a new parameter (Mean Damage Parameter), which combines the dissipated energy concepts and the phenomenological approach (number of cycles which cause its fail). This paper shows the basics of this parameter, and the results obtained in a study carried out to evaluate its efficiency as a tool for the improvement in the laboratory mix design.