An extensive experimental and analytical investigation is being currently carried out on the mechanisms leading to the initiation and propagation of fatigue damage in the top layers of asphalt concrete pavements when subjected to various types of loading. One of the major goals of the investigation is the development and finite element implementation of a triaxial, strain rate sensitive, history and temperature dependent constitutive model for asphalt concrete under arbitrary states of stress.

Because of the hierarchical formulation of the model, the analyst can activate, at will, those features of the model which he considers relevant to his specific interests. Explicit procedures are suggested for the experimental determination of the parameters. As a minimum, only uniaxial test results are needed for determination of the basic parameters. An actual example of such a procedure is presented.

In its current, prototype formulation, the model has been implemented in the finite element code CAPA3D. Results of the utilization of CAPA-3D for the investigation of the dynamic non-linear response of asphalt concrete pavements are reviewed in the last part of this contribution.