Geocomposite Capillary Barrier Drain (GCBD) for Limiting Moisture Changes in Pavements

This article presents research into a prototype for geocomposite capillary barrier drains (GCBD), as created by the Minnesota Road Research Facility (MnROAD) and funded by the NCHRP Highway IDEA Program and the FHWA Pooled Fund project, and is a collaboration of three organizations including the Minnesota Department of Transportation (MnDOT). GCBD is similar to standard composites, the difference being that the transport layer of GCBD allows for water transmission with negative water pressures, while conventional composites are designed for saturated flow. The article provides an outline of the test section design, located in Minnesota near Minneapolis/St. Paul. Although results have not been finalized, researchers expect GCBD to increase both rates and amount of drainage possible when compared to traditional geocomposites.