Assessing Remaining Service Life and Structural Performance of Substandard Airfield Pavement for Low-Volume Traffic with an Accelerated Aircraft Loading Simulator

A field evaluation to investigate the remaining service life and structural capacity of a substandard airfield pavement under accelerated aircraft traffic is reported in this paper. The pavement test section consisted of a relatively thin asphalt concrete layer with a considerably thin base course. A single-wheel aircraft simulator was used to mimic the loading conditions of two cargo aircrafts, C-17 and C-130. Two operating tire inflation pressures, namely normal tire pressure (NTP) and approximately 20% below NTP (reduced tire pressure), were investigated as a strategy to improve the pavement's service life while maintaining the total aircraft load. The rut development was the primary pavement distress measured while the pavement structural capacity was routinely assessed with a heavyweight deflectometer and a portable lightweight deflectometer (LWD) at selected traffic intervals. PCASE software was also used to computationally predict the service life of the selected substandard airfield pavement. Overall, this nonstandard airfield pavement exhibited acceptable performance for an expedient aircraft mission with a C-17 (less than 100 passes) or a sustainment aircraft mission with a C-130 (less than 5000 passes). From this study, reducing the operating tire pressure did not influence the allowable number of passes to failure, considering the failure criterion as a rut depth of 25.4 mm. It was found that the LWD showed promise to monitor deterioration of substandard airfield pavements during aircraft operations. The PCASE results were not in full agreement with the field study and outlined the critical need of improving the current evaluation technique specifically for substandard airfield pavements.