Methodology for Determining Performance Life of Hot-Mix Asphalt Mixtures

A critical component of the life-cycle cost analysis for staged design and rehabilitation of flexible pavements is to estimate the service lives of various hot-mix asphalt (HMA) mixtures, which in some cases is carried out subjectively. This paper describes a process for using the existing data to develop an objective and data-driven process for estimating the service lives of common HMA mixtures. Spatial information along with construction records and distress and functional condition logs are merged to assess the “cradle-to-grave” service lives and deterioration patterns, statewide or regionally. One of the most challenging steps was linking separate databases to compile a comprehensive pavement performance database. The end result was an online tool that enabled the extraction of HMA service life data and descriptive statistics of several thousand road sections. The probabilistic performance life of each common mix was then estimated through an integrated approach of survivability analysis that considers the historical longevity of mix types, the age of the HMA surface course, distress history–based life predictions, field case study life predictions, and department of transportation personnel perceived service lives. The results as applied to Texas data showed bimodal longevity distributions of service life. In general, the mean service life of the analyzed dense-graded mix met or exceeded the mean perceived service life expressed by two dozen pavement engineers statewide. However, a fraction of the projects exhibited shorter lives because of a number of technical and institutional factors. Overall, the proposed methodology proved to be a consistent process when assessing HMA service life.