Quantifying overall damage and healing behaviour of asphalt materials using continuum damage approach

Abstract

A test and analysis method to determine both the damage and healing characteristics of an asphalt composite using the same test specimen is presented. The test involves applying multiple stretches of load cycles, each separated by a period of zero load introduced at different levels of stiffness reduction. The analytical procedure involves using the modified correspondence principles and viscoelastic continuum damage mechanics to model damage and healing properties of the composite. The results obtained using two different asphalt mortars confirmed the findings from previous researchers that the characteristic pseudo-stiffness versus damage relationship for each material was independent of testing conditions. More importantly, this study demonstrated that the aforementioned relationship was also independent of the rest periods introduced intermittently during the fatigue test. Results also show that healing defined in terms of the change in the state variable of damage was independent of the conditions used to induce fatigue damage.