Field Performance Evaluation of Pavement Sections with High Polymer-Modified Asphalt Concrete Overlays

When pavement rehabilitation becomes necessary, asphalt concrete (AC) overlays have been one of the most common treatments used by the Virginia Department of Transportation (VDOT) for maintaining or rehabilitating aged pavements. However, for composite pavements or cracked AC pavements, differential movements across any cracks or joints underlying a new AC overlay due to the combined effects of heavy wheel loads and temperature fluctuations result in physical tearing of the AC overlay. Thus, the long-term performance of many AC overlays will highly depend on their ability to resist reflective cracking from all pavement types. In 2014, VDOT initiated a research study to evaluate the effectiveness of using high polymer-modified (HP) asphalt binders in surface AC mixtures. The results were promising enough to support a field study investigating the use of HP binders in asphalt mixtures over jointed concrete pavement (JCP) as a reflective crack mitigation technique or when deemed appropriate as a tool for increased crack resistance on higher volume facilities. Since 2015, HP AC overlays have been placed at several sections over existing JCP and asphalt pavements to mitigate reflective cracking. The objective of this paper was to evaluate the viability of using HP AC mixtures as a tool to mitigate reflective cracking or when deemed appropriate as a tool for increased crack resistance on higher volume facilities. Distress survey data collected from VDOT pavement management system of HP field sections were compiled and compared alongside their control polymer modified asphalt (PMA) sections. Overall, none of the evaluated mixtures (HP or PMA) was able to totally stop reflective cracking. However, the HP sections showed the most promising performance after five years (2015-2020) from construction regardless of the traffic level and the pre-existing pavement conditions.