Geotextile products are engineered to provide cost-effective solutions to meet specific requirements in civil engineering construction, there are at least ﬁve major functions of geotextile: Separation, Reinforcement, Filtration, Drainage, and Protection. Geotextiles are available in a variety of structures and polymer compositions designed to meet required applications. Generally geotextiles are designed to be strong, durable, chemically inert and resistant to the effects of site-specific ground conditions, weather and aging.
Separation is the process of preventing two dissimilar materials from mixing. In this function, a geotextile is most often required to prevent the undesirable mixing of fill and natural soils or two different types of fills. A geotextile can be placed between a railroad subgrade and track ballast to prevent contamination and resulting strength loss of the ballast by intrusion of the subgrade soil. In construction of roads over soft soil, a geotextile can be placed over the soft subgrade, and then gravel or crushed stone placed on the geotextile. The geotextile prevents mixing of the two materials.