Monitoring Geosynthetics in Local Roadways (LRRB 768) 10-Year Performance Summary

Geosynthetics have been used for many years to construct bituminous pavements, although the performance of these roads has not been well-documented. The main objective of this project was to identify and quantify any pavement performance benefits resulting from the installation of geosynthetics in pavement base and subbase layers. Potential benefits would include a reduction in longitudinal and transverse cracking, decreased rutting, and improved ride quality. Pavement performance was measured on 13 local roads in northwestern Minnesota by MnDOT's Pathways van, which performed annual condition surveys of each road segment each fall since 2001. The Pathways data were analyzed for ride quality, rutting, and cracking over a 10-year period to determine what, if any, benefit could be derived from using geosynthetics. The performance data were considered on a yearly and long-term basis. The data showed that type V fabric sections had decreased ride quality, rutting resistance, and surface rating when compared to control sections. Geogrid sections had increased ride quality, rutting resistance, and surface rating when compared to control sections. The saw & seal section generally had better pavement performance than the control sections, but there was only one such section in this study. Based on the results of this study, type V geosynthetic fabrics are not recommended to be used in cases where increased pavement performance or longer pavement life are expected. However, geogrids did provide better ride quality, structural capacity, and cracking resistance than pavements without geogrids.