Evaluation, Local Calibration, and Validation of Performance Prediction Models in AASHTOWareTM Pavement ME Design Software Using NCAT Test Track Data by Xiaolong Guo A dissertation submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Auburn, Alabama May 6, 2017 Keywords: Pavement ME Design, Local Calibration, Input Level 1 Copyright 2017 by Xiaolong Guo Approved by David H. Timm, Chair, Brasfield & Gorrie Professor Randy West, Director of National Center for Asphalt Technology Nam Tran, Associate Research Professor Rod E. Turochy, Associate Professor of Civil Engineering Abstract The AASHTOWareTM Pavement ME Design software was adopted by the American Association of State Highway and Transportation Officials (AASHTO) for structural pavement designs. The performance prediction models in the software were only calibrated based on a national database of pavement sections in the U.S. and Canada. These models may not apply to local pavement designs due to insufficient adequacy. The National Center for Asphalt Technology (NCAT), equipped with a full-scale accelerated pavement Test Track and asphalt materials laboratory, supported this study on evaluation, local calibration, and validation of the rutting, bottom-up fatigue cracking, and IRI models. The NCAT database was developed with research-grade detail and accuracy and was locally-based regarding the information of materials, traffic, and climate, and field performance. In the process of local calibration, automation was used during software runs and data compiling to minimize human interaction with the computer. Considerable labor savings (100% reduction) and time savings (nearly 35% reduction) were gained. As for evaluation results, over-predictions by the nationally-calibrated rutting and bottom-up fatigue cracking model were seen for a majority of experimental sections, and local calibration reduced bias and standard error of the estimate. The IRI prediction by the nationally-calibrated model was only accurate between 35 in./mile to 65 in./mile, and local calibration insignificantly improved the IRI prediction accuracy. The improvement of model accuracy was adequately validated for the locally- calibrated rutting and bottom-up fatigue cracking model, but not for the locally-calibrated IRI model, using independent local datasets. The recommended calibration coefficients should be evaluated based on a local database if they are intended for other design conditions. The automation method is recommended for future calibration studies since benefits in saving time and labor cost. ii Acknowledgments I would like to thank my academic advisor Dr. David H. Timm for his guidance on my Ph.D. program. His rigorousness, patience, and expectation motivated me to reach deeper and be more involved in the research of pavement engineering. I not only learned a wealth of knowledge and skills in the field of pavement design and asphalt technology, but also formed my habit of independent thinking and trained myself with professionalism, reasonability, and a sense of sympathy. It is his advice that strengthens my confidence to insist on the study until a completion of this program. I would like to thank Dr. Randy West for taking the time to advise me about my work and participate as one of my committee members. I am also truly grateful to Dr. Nam Tran and Dr. Rod Turochy for their time and endeavor to guide and inspire my study. I would like to thank Dr. Daniela Marghitu for taking the time to serve as a university reader for my dissertation. I am thankful to Dr. Robbins, Dr. Powell, Dr. Rodezno, Jason Nelson, Adam Taylor, and Dr. Heitzman for their assistance in carrying out research and experiments. I would like to thank Xiao Zhao, Zhenyu Wang, Hao Wu, Michael Vrtis, Bing Han, Wangyu Ma as well as other students of the civil engineering program here for their kind help in my life. Finally, I would like to thank my parents for their selfless care and encouragement during my study. I would like to thank my relatives and friends in China for their support during my study. iii Table of Contents Abstract ......................................................................................................................................................... ii Acknowledgments ........................................................................................................................................ iii Table of Contents ......................................................................................................................................... iv List of Figures ............................................................................................................................................. vii List of Tables ................................................................................................................................................ x Chapter 1 Introduction .................................................................................................................................. 1 1.1 Background ......................................................................................................................................... 1 1.2 Objectives ........................................................................................................................................... 3 1.3 Scope of work ..................................................................................................................................... 3 Chapter 2 Literature Review ......................................................................................................................... 5 2.1 Overview of the Pavement M-E Design software............................................................................... 5 2.2 Performance prediction models .......................................................................................................... 8 2.2.1 Rutting model ............................................................................................................................... 8 2.2.2 Bottom-up fatigue cracking model ............................................................................................ 10 2.2.3 IRI model ................................................................................................................................... 12 2.3 Recommended local calibration procedures ..................................................................................... 13 2.4 Previous efforts of local calibration .................................................................................................. 18 2.5 Automation ....................................................................................................................................... 51 iv Chapter 3 Methodology .............................................................................................................................. 54 3.1 NCAT database ................................................................................................................................. 54 3.1.1 Material characterization ............................................................................................................ 55 3.1.2 Traffic loading characterization ................................................................................................. 62 3.1.3 Climate characterization ............................................................................................................ 63 3.1.4 Distress measurements ............................................................................................................... 65 3.2 Evaluation, calibration, and validation process................................................................................. 65 3.2.1 Rutting model ............................................................................................................................. 66 3.2.2 Bottom-up fatigue cracking model ............................................................................................ 69 3.3.3 IRI model ................................................................................................................................... 72 Chapter 4 Results and Discussion ............................................................................................................... 73 4.1 Rutting model (evaluation and local calibration) .............................................................................. 73 4.2 Rutting model (validation) ................................................................................................................ 77 4.3 Bottom-up fatigue cracking model (evaluation and local calibration) .............................................. 81 4.4 Bottom-up Fatigue cracking model (validation) ............................................................................... 85 4.5 IRI model (evaluation and local calibration) .................................................................................... 88 4.6 IRI model (validation) ....................................................................................................................... 91 Chapter 5 Automation ................................................................................................................................. 96 5.1 Scheme of automation ......................................................................................................................