Investigation of the Use of Open Graded Friction Courses in Wisconsin

摘要

The use of open-graded friction course (OGFC) mixtures has changed over recent years across the United States. The OGFC mixtures designed and produced prior to 2000 experienced numerous performance problems that resulted in premature failures due to raveling, debonding and stripping of the underlying layer. Additionally the use of these mixtures in northern climates created additional seasonal problems with winter snow and ice control compared to dense graded Hot Mix Asphalt (HMA). As a result of these failures almost all Northern states that tried, and in some cases, frequently used OGFC mixtures discontinued their use. In or around 2000, several states and the National Center for Asphalt Technology (NCAT) started recommending and using European type OGFC mixtures with larger coarse aggregate, less fine aggregate, higher air voids (18 to 20 percent+) and polymer modified asphalt and/or fibers (1). These new generation OGFC mixtures (as they are called) were promoted as a method to improve poor performance due to raveling (caused by aging of the AC binder and thin asphalt films on the aggregate) and pavement fat spots and areas of bleeding (caused by drain down of the AC binder from the aggregate during the construction process). As Wisconsin is looking at increasing its usage of the perpetual pavement concept, OGFC may provide another option for use as the renewable surface layer.