Geokomposite

Geocomposite is a product used in civil and environmental engineering that consists of two or more geosynthetics or geosynthetic-like materials combined into a single unit to perform one or more functions in contact with soil or water. By uniting materials with complementary properties, geocomposites provide drainage, filtration, separation, reinforcement, or barrier capabilities in a thinner or more easily installed form than separate components.

Common configurations include drainage geocomposites, which pair a drainage core (such as a geonet) with geotextile layers to collect and convey subsurface flow; reinforcement geocomposites, where geotextiles are bonded to geogrids or geocells to improve soil stability and bearing capacity; and geosynthetic clay liners (GCLs), which place bentonite clay between geotextiles to create low-permeability barriers. There are also filter/separator geocomposites that combine geotextiles with drainage layers to prevent soil intrusion while enabling drainage.

Applications span landfills, retaining walls, slopes and embankments, road and rail subgrades, drainage layers under pavements, canal and reservoir linings, and erosion control projects. Advantages include reduced layer thickness, simpler installation, and the integration of multiple functions into a single product, which can lower project costs and increase design flexibility. Key design considerations are hydraulic performance (transmissivity and permeability), mechanical strength and stiffness, puncture resistance, chemical compatibility, and durability. Standards and testing for geocomposites cover their hydraulic, mechanical, and environmental performance. See also geosynthetics, GCL, geotextile, geogrid.