The classic application of a geotextile as a liquid barrier is paved road rehabilitation, here the non-woven geotextile is placed on the existing pavement surface following the application of an asphalt. The geotextile absorbs asphalt to become a waterproofing membrane minimizing the vertical flow of water into the pavement structure. Geotextiles are used in paved roads and runways to provide reinforcement, separation, drainage, and filtration. It helps to control the development of common pavement distress features such as rutting and cracking which can compromise the safety and durability of the runway and helps to distribute loads evenly.
This is accomplished by structural reinforcement of the base aggregate layer, controlling infiltration into moisture-susceptible layers, and preventing contamination of structural layers by the migration of fines from underlying soils. These functions help preserve and in some cases, enhance the structural integrity of the constructed pavement layers.