The objectives of this paper are to present an approach using statistical analysis and Miner's law to predict the fatigue performance (crack initiation) of the WesTrack test sections. A strain function, calculated by a layered-elastic program, was statistically determined in terms of temperature at the bottom of the asphalt layer, temperature gradient, subgrade modulus, air-void content, and asphalt content. With integration of laboratory fatigue test results, strain calculation, and Miner's law, the methodology produces the output in terms of cumulative fatigue damage versus cumulative repetitions for both wander and no-wander cases. Lack of consideration of nonlinear stiffness deterioration of asphalt concrete, crack propagation, and an appropriate correction factor makes long-term fatigue performance prediction conservative and not fully compliant with the condition survey data from WesTrack. The simulation indicated that the WesTrack coarse mixes took longer to initiate fatigue cracks than the fine and fine-plus mixes did but may propagate cracks faster in cold weather.
Abstract