Flexible Pavement Resiliency and Mitigation Strategies Following Adverse Environmental Events

Water accelerates flexible pavement damage in various ways, including subgrade and granular pavement materials strength reduction, frost heave, swelling of expansive subgrade soils, and asphalt binder stripping of aggregate in asphalt concrete (AC) mixes. This paper presents case studies of AC pavement sections in the U.S. that withstood high moisture events with limited effect on pavement performance and no immediate need for major maintenance or rehabilitation actions. The case studies comprise pavement sections in Florida and Louisiana that were subjected to catastrophic flooding events, a pavement section in Delaware that is constantly exposed to tidal water level variations, and pavement sections in Montana and Minnesota that experience seasonal freeze-thaw. These cases illustrated that flexible pavements could withstand climatic changes when appropriately designed and constructed. Mechanically or chemically stabilized subgrade, proper drainage, and/or minimizing plastic fines in unbound layers are all techniques that could effectively control moisture damage.