Greenville county, south carolina, constructs permanent paved surfaces on approximately 20 mi of existing gravel road each year. Thecounty engineer sought to protect his new low-cost pavement from premature degradation and more frequent maintenance by including an appropriate geotextile as a separator between the subgrade and the pavement structure. The physical properties required to make the geotextile an effective long-term separator include both strength properties, which resist the forces of coarse aggregate being pushed into the subgrade, and hydraulic properties, which prevent the pumping of fine soils up into the coarse base aggregate while still allowing forpore water pressure dissipation from the subgrade. The geotextile strength and hydraulic properties necessary to survive construction and to provide long-term filtration and separation between the subgrade and the base aggregate are evaluated by testing of exhumed geotextile samples and visual pavement condition surveys for a trial installation. This paper appears in transportation research record no. 1291, Fifth international conference on low-volume roads, may 19-23, 1991, raleigh, north carolina, volume 2.
Abstract