Effects of Improved Density Techniques on the Field Performance of Asphalt Pavements

Abstract

The in-place density of asphalt pavements significantly influences their long-term performance and service life. This study assessed the impact of increased in-place density techniques on field performance by analyzing two field projects. Field project 1 included three test sections: Evotherm warm-mix asphalt (WMA), increased asphalt content (Plus AC), and a control section. Field project 2 evaluated four asphalt rehabilitation routes, categorized into two sections: control and temperature-segregated sections. Across both projects, 13.95 lane miles were evaluated. The control sections in field project 2 were areas with temperature differentials less than 14°C from the specified compaction temperature, whereas the temperature-segregated sections were colder areas with temperature differentials exceeding 14°C. Structural capacity data was collected from field project 1 using a falling-weight deflectometer. Field performance data from both projects was used to assess the impact of increased in-place density techniques on pavement performance. The results showed that pavement sections with enhanced density techniques exhibited significantly better structural capacity than the control section. Generally, Evotherm WMA and Plus AC increased-density techniques caused a significant improvement in rutting resistance after 5 years in service. Additionally, these sections exhibited transverse-, longitudinal-, and alligator-cracking performances similar to or better than their corresponding control sections. The Evotherm WMA and Plus AC techniques effectively improved the pavement condition index (PCI) rating from “good” to “very good.” Furthermore, the temperature-segregation phenomenon negatively affected the PCI rating of two sections in field project 2, reducing it from “very good” to “good” compared with their corresponding control sections.