Characterizing Fundamental Rutting Property of Asphalt Concrete from Multiscale Simulative Tests using an Inverse Approach

Objectives: The proposed research will develop an innovative method to use Inverse Approach to characterize three fundamental properties (the elastic modulus, the yielding strength, and an internal loading transfer parameter to represent mastics-aggregate skeleton interaction). These three parameters represent the rutting resistances of asphalt so that different scales of simulative tests and SPT tests can have a common basis for comparison and evaluation purposes. Significance: Simulative tests have complicated contact and boundary conditions. It is hard to calculate fundamental material properties such as modulus and yielding strength from simulative tests. Nevertheless, there are about 1500 units of simulative testing devices in the world. A method to calculate fundamental material properties such as modulus and yielding strength will significantly enhance the capability of simulative testing and have important impacts on the paving industry by saving testing costs, better screening problematic mixes, and more accurately predicting mix performances. Potential Impacts on State of Practice: Due to the non-representative specimen stress-strain field of simple performance tests, the SPT test results have limitations in that models using SPT test results do not realistically predict the performance of asphalt pavement in the field. Simulative tests are traditionally used as a pass-fail test to evaluate asphalt mixes before they can be used for construction projects. If fundamental material properties can be calculated from simulative tests, the evaluations of mix designs can be integrated into pavement design by supplying the required parameters characterized from simulative tests for pavement design