Field and Theoretical Evaluation of Thermal Fatigue Cracking in Flexible Pavements

Abstract

Thermal cracking in flexible pavement occurs when the tensile stress exceeds the tensile strength of hot-mix asphalt at a given temperature or when fluctuating stresses and strains caused by temperature variation lead to a buildup of irrecoverable deformations over time. The objective of this study was twofold: (a) to quantify the measured strain magnitude associated with thermal fatigue through field measurements and (b) to present a three-dimensional, finite element (FE) model that accurately simulated thermal fatigue in flexible pavement. Results of the experimental program indicated that pavement response to thermal loading was associated with a high strain range, reaching a maximum recorded value of 350 um/m. This finding confirms the hypothesis that the criticality of thermal fatigue arises from the high stress-strain level exhibited in each cycle rather than its frequency, which is usually the critical factor in load-associated fatigue cracking. Moreover, the developed FE model accurately simulated...