Long-Term Performance of Reflective Cracking Mitigation Techniques in Nevada

Hot-mix asphalt (HMA) overlay is one of the commonly used methods for rehabilitating deteriorated pavements. The Nevada Department of Transportation (DOT) uses HMA overlays as a rehabilitation technique for the majority of the state's flexible pavements. One major type of distress influencing the life of an overlay is reflective cracking. In the past, Nevada DOT has experimented with a number of techniques— such as cold in-place recycling, reinforced fabrics, stress relief courses, and mill and overlay—to reduce the impact of reflective cracking on HMA overlays. Several projects were constructed under each category. The long-term field performance of various Nevada DOT reflective cracking mitigation techniques was evaluated; the techniques were used on flexible pavements at 33 field projects. Performances of the various projects were analyzed by fatigue, transverse, and block cracking measurements from Nevada DOT's pavement management system data. In addition, the statistical approach called principal component analysis was used to asses the effectiveness of each of the reflective cracking techniques. The study indicated that cold in-place recycling and mill and overlay were the most effective treatments for reflective cracking of HMA overlays over HMA pavements under Nevada's conditions, except when the existing pavement experiences severe alligator cracking. In such situations, it is recommended that HMA pavement be subjected to reconstruction or full-depth reclamation.