Identifying indicators for fatigue cracking in hot-mix asphalt pavements using viscoelastic continuum damage principles

A critical distress in asphalt concrete pavements is fatigue cracking, which results in decreased ride quality and fuel economy, and provides an avenue for water intrusion, which causes a pavement system to deteriorate rapidly. Given the poor state of the infrastructure network, changes are needed in the current mixture design process to promote innovation and alternative approaches to production. This study addressed this need by pursuing the following objectives: (a) relate mixture stiffness, fatigue, and pavement system characteristics for performance-based mixture design; (b) identify a simplified viscoelastic continuum damage (S-VECD) output parameter that most clearly distinguishes between poor and satisfactory performance when combined with dynamic modulus information; and (c) evaluate the impact of recycled materials on performance indicators for fatigue cracking. The results show that a pavement structure selection process related to the S-VECD failure criterion produces better performance predictions than does a stiffness-based approach. Promising correlations with performance exist for the pseudostiffness at failure and storage modulus for an Interstate pavement structure, phase angle for a state highway surface and base course, and model term alpha for the same state highway base course.