Evaluation of the Long-Term Performance of Woven Geotextile Used between Base Course and Subgrade of a Paved Road

Abstract

The purpose of this research was to investigate the properties of the exhumed geotextile from a low-volume road on the Virginia Department of Transportation network. The exhumed geotextiles have been in service for 23 years, which provided an opportunity to evaluate the longevity of the materials as well as to make assessments of how it relates to the changes in material properties. During this investigation, subgrade and base course materials were also obtained from the same site and an experimental program was developed to evaluate the effectiveness of the exhumed geotextiles for separation, stabilization, and filtration for the base course thicknesses of 4, 6, and 8 in. The results from this study combined with the results from the previous studies conducted at the same site showed that when the geotextile is placed between the subgrade and base course, the thinner the pavement section, the more evident the effectiveness of the geotextile improvements. One important finding of this research was that the placement of a geotextile reduced the particle breakage caused by abrasion under the applied transient loads. This was observed as a stabilization effect of the geotextile inclusion. As a general conclusion, for low-volume roads with relatively thin pavement sections, properly selected geotextiles provide benefits for separating the subgrade and base course (minimizing pumping), filtering infiltrated or ground water, and stabilizing the road profile. These benefits become more apparent when the thickness of the base course is less than 8 in.