Field Performance of Thin Open-Graded Friction Overlays

Open-graded friction course (OGFC) mixtures have been used by several agencies as a wearing surface to improve the functionality of the roadway by minimizing splash and spray, increasing wet weather visibility, improving friction resistance, and reducing noise levels. However, thin OGFC overlays can also help maintain or improve pavement condition and extend pavement life when used as preservation treatments. The objective of this study was to evaluate the field performance of five thin OGFC overlays used for pavement preservation. The results obtained after seven years of service show that overall, the sections have exhibited good durability performance and structural health, which are capable of extending the life of the pavement. The functionality of the OGFC layer has decreased over time, suggesting that some of the added benefits of open-graded mixtures, such as permeability and noise reduction, may be lost within the first few years of service.