Review of mechanistic-empirical modeling of top-down cracking in asphalt pavements

Abstract

Top-down cracking has been identified worldwide and is regarded as a major type of asphalt pavement distress. Along with a comprehensive review of the existing work, this study is intended to propose a roadmap for developing a mechanistic-empirical model and associated design software for top-down cracking in asphalt pavements. This paper reviews eleven sub-models relevant to material, structure, traffic, and climate to account for the key factors that affect top-down cracking. Over 120 published studies are located and reviewed in terms of modeling techniques, model types, and model components. In addition, the methods and sources to identify and collect the data required to develop these sub-models are presented. Within the scope of this work, this study discusses several sub-models as examples and provides a roadmap for future development. The introduced sub-models emphasize some critical issues, such as the modulus gradient due to non-uniform aging, different cracking mechanisms, and computation of the J-integral (energy release rate) that drives the crack downward from the pavement surface. Finally, this study provides an assembling plan to put all of the sub-models together into a Top-Down Cracking Program, which could predict and calibrate the growth of top-down cracking in asphalt pavements.