Reliability-Based Specification for Asphalt Concrete Pavements

The use of volumetric-based specifications that utilize air void and asphalt content for the quality control of asphalt pavements is a major concern as there is a lack of fundamental correlation between these mixture properties and long-term pavement performance. In addition to that, the input variabilities' influence on target reliability and pavement performance is not addressed in these volumetric-based specifications. The aim of this article is to introduce a reliability-based specification for the quality control of top-down cracking in asphalt concrete pavements. The reliability-based specification criteria are developed for two traffic level categories and using design inputs such as hourly equivalent single axle load traffic, asphalt layer thickness, base modulus, and dissipated creep strain energy limit. For the development of the reliability-based specification, several field pavement sections with well-documented performance history and high-quality laboratory and field data were analyzed using the mechanics-based design framework for variability conditions that are representative of actual field conditions. Variation in dissipated creep strain energy limit and asphalt concreter layer thickness has been observed to influence target reliability and overall pavement performance significantly, in comparison with base modulus and hourly equivalent single axle load traffic. The proposed reliability-based specification can complement existing performance-based specifications for the quality control of top-down cracking in asphalt concrete pavements.