Predicting Rutting Performance of Flexible Airfield Pavements Using a Coupled Viscoelastic-Viscoplastic-Cap Constitutive Relationship

Abstract

Rutting performance of airfield pavements is predicted using mechanistic-based constitutive relationships for both asphalt and granular layers. Pavement analysis using nonlinear damage approach-airfield pavements (PANDA-AP) is used that encompasses a coupled viscoelastic–viscoplastic constitutive relationship to model the rutting distress in the asphalt layer and a modified extended Drucker-Prager-Cap (D-P-Cap) is used to predict permanent deformation induced in granular layers due to aircraft traffic. The D-P-Cap model captures the permanent deformation due to both shearing and densification of granular layers. Experimental test results from resilient modulus, cyclic triaxial, dynamic modulus, and flow number tests are used to fully calibrate the constitutive relationships. The calibrated constitutive relationship is then validated against independent lab experiments. The calibrated model is used to predict the performance of airfield pavement sections tested at the National Airfield Pavement Test Facility (NAPTF) of the Federal Administration Aviation (FAA). It is shown that the presented mechanistic-based constitutive relationships can be effectively used to predict the rutting performance of airfield pavements when subjected to high aircraft tire pressure.