Characterization of Cross-Anisotropic Aggregate Base Behavior From Stress Path Tests

A new methodology is presented in this paper for determining cross-anisotropic aggregate properties, i.e., directional dependency of moduli and Poisson's ratios, from stress path testing. The proposed laboratory characterization procedure requires conducting large stress excursion tests performed under slightly different stress path slopes at similar stress states that are representative of pavement wheel loading conditions. In accordance, cross-anisotropic aggregate properties are determined by varying slightly the stress path slopes during testing and then by employing an error minimization approach to interpret the test results. The solution methodology adopted also satisfies positive strain energy requirements. Such an anisotropic material property set obtained from following the proposed methodology would essentially be useful in the finite element analysis of the anisotropic and stress dependent granular material behavior often observed in unbound pavement layers.