Reflective cracking relief interlayer for asphalt pavement rehabilitation: from development to demonstration

Abstract

Reflective cracking is one of the major type of distresses associated with the use of asphalt concrete (AC) overlay for rehabilitating deteriorated asphalt pavements. This paper briefly describes the research efforts completed in Nevada to identify the best promising techniques to mitigate reflective cracking in AC overlays under Nevada’s climatic and materials’ conditions. The main outcome of the study was the development of a preliminary performance-based mix design specification for an experimental stress relief course (referred to as ESRC) to be placed between the AC overlay and the milled AC surface. Consequently, in summer of 2015, the Nevada Department of Transportation (NDOT) implemented the developed specification on a demonstration project on US 95 in southern Nevada. The project included test sections with three different strategies: (1) AC overlay on top of the ESRC mixture, (2) AC overlay on top of the NDOT fine-graded Type 3 mixture (SRC-T3), and (3) AC overlay without any stress relief layer. An extensive laboratory evaluation was conducted on all three mixtures using both laboratory-mixed laboratory-compacted and field-mixed laboratory-compacted mixtures. Core samples were also collected after construction and were evaluated for in-place thickness and air voids as well as resistance to reflective cracking. The data showed promising results for the ESRC mixture in terms of its resistance to fatigue and reflective cracking while maintaining an acceptable level of stability and resistance to rutting. A windshield survey conducted approximately 13 months after construction showed no distresses in any of the surveyed sections. In summary, the study showed a very good performance for the ESRC mixture thus far, making it a promising technique for reflective cracking mitigation in Nevada.

Keywords:

• AC overlay
• reflective cracking
• stress relief course
• trial sections
• performance

Acknowledgements

Mr Ye Yuan is graciously acknowledged for his help during sample preparation and testing. The content of this study reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the sponsor at the time of publication. The authors would like to acknowledge the Nevada Department of Transportation (NDOT) for sponsoring this research work, providing the initial field specimens, and monitoring the field performance.

Disclosure statement

No potential conflict of interest was reported by the authors.