Mechanical responses and viscoelastic properties of asphalt mixtures under heavy static and dynamic aircraft loads

The introduction of larger aircraft on flexible airfield pavements has led to a need for asphalt mixtures capable of sustaining such heavy loads. This laboratory and analytical study investigated the mechanical responses of a number of modified asphalt mixtures to identify their potential for use in airfield aprons and taxiways that were subjected to heavy, static, or slow-moving aircraft loads. The airfield flexible pavement section constructed at the FAA's National Airport Pavement Test Facility Construction Cycle 1 was modeled by using the three-dimensional finite element analysis software ABAQUS. Laboratory-compacted specimens of each modified asphalt mixture were tested by using AASHTO standards to determine volumetric properties and mechanical responses. The effects of static and dynamic aircraft loading were evaluated in ABAQUS with the material properties of the mixtures determined in the laboratory. On the basis of the findings of this study, it appears that several mixtures more commonly used in highway pavements, including modified mixtures, warm-mix asphalt, and reclaimed asphalt pavement, perform similarly to or even outperformed the F'A A standard asphalt mixture. The results of this initial study support the idea that an opportunity exists for airports to implement emerging asphalt paving materials without compromising the pavement design life.