Many studies indicate that geosynthetic reinforcement can help prolong the service life of a flexible pavement by reducing the required structural number of the pavement, and improving rutting resistance and subgrade capacity. However, not enough long-term geosynthetic field performance studies are available to help understand the benefits of reinforcing a pavement on a reasonably good subgrade soil. To that end, in 2015, Alberta Transportation constructed a geogrid reinforced test section on Hwy 63 north of Wandering River. A contiguous segment of the highway with the same pavement structure, environment, traffic, and similar subgrade was selected as an unreinforced control section against which to compare field performance. This highway is the major route to Fort McMurray and the oil sands and carries annual average daily traffic (AADT) of 4,000, with approximately 28 percent trucks. The highway is part of the oversize overload highway network and sees some very unique truck and axle configurations. The pavement structure of the geogrid reinforced test and unreinforced control sections was designed for staged construction. The second (or final) stage pavement was delayed to accelerate pavement distress development and pavement performance comparison.
Performance data such as International Roughness Index (IRI), rutting measurements, Laser Crack Measurement System (LCMS), Falling Weight Deflectometer (FWD), and pavement surface condition from visual inspections were collected for six consecutive years. These data were analyzed for both the geogrid reinforced test section and the unreinforced control section. This study did not find any significant differences in the analyzed data or visual condition between the reinforced and the unreinforced sections over six years. This paper has also attempted to investigate the possible reasons behind these findings. Both sections have reached a condition where further delay in final stage pavement construction would be imprudent. The longer-term performance will be monitored after the final stage pavement construction and reported in the future to confirm the findings.