Calibration of AC Reflection Cracking Model in AASHTOWare Pavement ME Design for Nevada’s Conditions

The empirical design guide published by the American Association of State Highway Transportation Officials (AASHTO 1993), has been predominantly used by the majority of state highway agencies across the United States. Efforts were done by the National Cooperative Highway Research Program (NCHRP) under Project 1-37A to implement an improved design guide: “The Mechanistic-Empirical Pavement Design Guide (MEPDG).” The MEPDG uses a mechanistic-empirical (ME) procedure that predicts future pavement conditions based on analyzing the pavement responses.This Thesis describes the research efforts done in order to calibrate the new asphalt concrete (AC) reflection-cracking model implemented in the AASHTOWare Pavement ME Design and developed under the NCHRP project 1-41: “Models for Predicting Reflection Cracking of Hot-Mix Asphalt Overlays.” For this purpose, several Nevada Department of Transportation (NDOT) pavement sections including State Routes, Interstate Routes, and US Routes were selected to conduct the calibration. The calibration of the reflection-cracking model was done to better match Nevada’s local conditions for climate, traffic, materials and was performed by optimizing/scaling the global calibration factors to reduce the sum of square error between predicted and measured distress data. As a result, local calibration coefficients were established for AC total fatigue cracking (bottom-up + reflective) and AC total transverse cracking (thermal + reflective). Elevation at the project’s location was found to influence the predictions, thus necessitating different local calibration coefficients