Reflective Cracking Relief Interlayer for Asphalt Pavement Rehabilitation: From Development to Demonstration

摘要

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