Airfield Flexible Pavement Responses under Heavy Aircraft and High Tire Pressure Loading

Abstract

This paper investigates airfield flexible pavement responses under heavy aircraft and high tire pressure loading considering the realistic aircraft tire–pavement interaction. An advanced three-dimensional finite element model was developed; it characterized the hot-mix asphalt layer as a viscoelastic material and used implicit dynamic analysis to predict time-and temperature-dependent pavement responses under various loading conditions. The tire loadings were simulated as moving loads having uniform and nonuniform contact stress distributions. To illustrate the effect of moving load, stationary loading analysis was conducted with the equivalent modulus determined from the middepth pulse time under moving loading. Two temperature profiles were considered in the analysis, as compared with the constant temperature profile using the average temperature. The pavement responses in the asphalt layer (tensile, compressive, and shear strains) under different loading conditions were calculated and analyzed in terms of pavement failure mechanisms. The results emphasized the importance of considering nonuniform contact stresses and moving load in airfield pavement analysis. On the contrary, applying the average temperature profile in summer was a conservative approach for predicting fatigue cracking potential but underestimated rutting or near-surface cracking potential in the airfield pavement. The rut depths in the asphalt layer were predicted by using mechanistic–empirical performance models and compared with the measurements from the full-scale test. The results suggested that specific calibration parameters should be developed to provide accurate prediction of rut depth for airfield pavements.