Calibration of Rutting and Fatigue Cracking Models for Flexible Pavement Design in Louisiana Using AASHTOWare Pavement ME Design

This paper presents the experience of local calibration of rutting and fatigue cracking coefficients in AASHTOWare pavement ME design (PMED) for asphalt concrete (AC) pavement, examining various methods tailored to different pavement types and their specific transfer functions. Three types of AC pavements were studied: new AC, semirigid, and AC overlay. The AASHTOWare Calibration Assistance Tool was employed throughout the study. The study identifies that an artificial neural network training-based method is advantageous for considering multiple coefficient interactions. For new AC fatigue cracking, the solver method proves efficient with a fixed damage index but is unsuitable for AC overlay cracking due to variable damage increments. The trial-and-error method is effective when dealing with one or two noninterfering coefficients. When predicted distress shows low sensitivity to coefficients, adjusting material parameters becomes essential. The study highlights the high sensitivity of fatigue cracking in semirigid pavements to modulus of rupture. Emphasizing the role of engineering judgment, the study recommends reducing the number of coefficients based on their physical meaning. Overall, this research underscores the importance of selecting appropriate calibration methods based on transfer function characteristics and coefficient interactions, offering a framework for effective calibration in PMED. The findings are grounded in the current editions of PMED, with a recognition that future changes in equations may necessitate different methods.