Abstract
Typically, a homogeneous pavement design is employed when constructing a road section. However, segments such as the approach intersection in a road section are subject to more severe loading due to the presence of static, accelerating, and decelerating traffic compared to the rest of the road section. The increase in traffic loading has negatively impacted the service life of approach intersections with high truck traffic volume in York Region. To ensure adequate durability, a more resilient pavement design is required for these approach intersections. Field results and past studies have indicated that relying solely on a volumetric design approach may not provide a comprehensive understanding of the asphalt mix under heavy traffic loading. Thus, the use of performance-related specifications could be utilized to produce high-performing asphalt mixes, resulting in an increased service life and reduced lifecycle cost. To evaluate this hypothesis, six Stone Mastic Asphalt (SMA) mixes, comprising three performance grade (PG) asphalt binders (PG70-28, PG76-28, and PG82-28) and two nominal maximum aggregate sizes (NMAS) of 9.5mm and 12.5mm, were produced under controlled laboratory conditions. The Disk-Shaped Compact Tension (DC(T)) Test was performed to characterize the low-temperature cracking resistance of the asphalt mixes, while the Illinois Flexibility Index Test (I-FIT) was used to evaluate the intermediate temperature cracking resistance. The Hamburg Wheel Tracking Test (HWTT) was employed to assess the shear resistance of the asphalt mixes. The results were compared to a recent plant-produced asphalt mix (WMA SP12.5FC2-PG70-28) used in York Region. A preliminary performance-based specification was developed to evaluate heavy-duty asphalt mixes, and a life cycle cost analysis was performed to determine the potential benefits of using a heavy-duty asphalt mix as a surface course over the conventional asphalt mix used in York Region.
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