Field Performance Evaluation of Asphalt Mixes at Approach Intersections: A Municipal Perspective

Asphalt concrete is among the materials which are most widely used for roads and airport pavements. These pavements over time suffer failure due to passing traffic loads and exposure to different environmental conditions. Typically, when designing a road at the project level, a homogenous pavement design is considered for the entire road segment meaning similar pavement materials and thicknesses are applied throughout a road segment. However, locations such as approach intersections undergo different loading scenarios which make these areas more vulnerable to pavement premature failures such as pavement permanent deformation/rutting and shoving during its service life. The difference in loading scenario is due to high shear stresses associated with vehicle’s stopping and accelerating and also slow traffic movement. As a result, sections such as approach intersections required more frequent treatments for addressing the pavement distresses which makes it both costly and time consuming. Annually, millions of dollars have been spent to compensate rutting failures in the pavement. Therefore, it is critical to agencies to select proper asphalt mixes such as high-performance asphalt mixes for the approach intersections to ensure adequate durability, quality, and safety. The proper mixes also save time and money and minimize environmental impact throughout the road’s lifecycle.With more people coming to York Region’s community every year, the number of vehicles and percentage of trucks transporting goods and services has increased significantly. Therefore, with an increase in temperature pattern in recent years in addition to this traffic increase, York Region is experiencing premature pavement failure, commonly rutting and some shoving, at some of its high-volume intersections. To study the in-service performance and root cause of the rutting and other distress at York Region’s approach intersection, six (6) approach intersections are selected for this study. The study consists of conducting rut depth measurement and geotechnical investigation such as ground generation radar (GPR) testing and collecting cores and borehole samples on the selected sites. This paper presents the field investigation results along with ranking methods to compare the susceptibility of the asphalt surface layer mix to rutting for the tested locations. This paper also explores ideas on how to extrapolate this project level information to the network level for the asset management purposes.