The Implementation of Dvorkin's Model on Predicting Effective Modulus of Open Graded Mixes

Open-graded mixes (OGM) are gaining more attention due to their noise reduction capability and better anti-skiding performance. However, due to the high air voids content, raveling is the most commonly observed distress type on pavements with OGM. In order to analyze the propensity of a given mix for raveling, in the previous work, the authors proposed the homogenization technique. It was notified that although Hirsch model performs quite well, it requires calibrations from laboratory tests. On the other hand, micromechanical modes did not show good agreement with laboratory tests. It was also observed that the micromechanical models could not capture the interactions among packed aggregates, and thus effective modulus was significantly lower than the experimental results at low frequencies. Based on these realizations, Dvorkin’s model which is based on contact theory, is supposed to perform better as notified by past researchers who applied this model for dense asphalt mixtures. To the best of authors’ knowledge, the performance of Dvorkin’s model in the case of OGM has not been studied. The aim of this paper is to demonstrate a procedure to implement Dvorkin’s model and highlight the performance of this model in predicting the effective modulus of OGM. The predicted results by this model were compared with (1) measured values from uniaxial compressive tests and (2) the predictions by micromechanical models. Sensitivity analyses were carried out to find out optimal input parameters.