Characterization of Fatigue Cracking Performance of Asphalt Mixes at the Federal Aviation Administration’s National Airport Pavement and Materials Research Center’s Accelerated Loading Facility

Asphalt airfield pavements undergo significant loading conditions because of the heavy loading and tire pressure conditions applied by various aircraft. Increasing aircraft wheel load and tire pressures along with environmental aging of asphalt can result in top-down surface fatigue cracking. The surface cracking can not only compromise the structural integrity of the pavements but also lead to the development of foreign object debris, which can affect the safety of aircraft operations. To better understand the behavior of materials used for airfield pavements, the Federal Aviation Administration (FAA) built the National Airport Pavement and Materials Research Center that houses a state-of-the-art Heavy Vehicle Simulator—Airfields (HVS-A) capable of loading test pavements under aircraft loading conditions. In this study, the FAA utilized the HVS-A to evaluate the fatigue cracking potential of a polymer-modified P-401 asphalt mixture produced with different warm mix asphalt technologies. Four different test sections were constructed, artificially and environmentally aged, and then loaded to induce fatigue cracking. Two of the four sections showed signs of fatigue cracking, and cracks became visible a couple of months after completion of the traffic tests. Extensive material characterization conducted on pre- and post-trafficked field cores showed a good correlation between different asphalt binder tests and the visual distress observations. The results of the study indicate existing asphalt binder and mixture characterization methods are sensitive enough to identify asphalt mixtures prone to top-down fatigue cracking distress and could be included in both purchase specifications and mixture design / acceptance specifications.