Geotextiles are used to separate two dissimilar materials such as two layers of soil with different properties . The purpose of separation is to maintain or improve the integrity and performance of both materials.. The geotextile ensure that the aggregate maintains its load-bearing ability. Without geotextile, subsoil and aggregate base intermix and load-bearing capacity are reduced .
This function is very important in all forms of roadways, railways, and parking areas , where the material used to form the base of the construction, usually some form of aggregate , is separated from the soil below.