ABSTRACT
Roadways include stiff aggregate layers, which support and dissipate traffic loads before reaching the subgrade soil. The aggregate stiffness must be preserved to reduce rutting severity. Geosynthetic-stabilisation can preserve the aggregate stiffness through aggregate-geosynthetic interaction at small strains. The performance of geosynthetic-stabilised roadways depends on the properties of both the geosynthetic and the selected aggregate. A study was completed at the University of Saskatchewan to determine the relative performance of two geogrids used to stabilise two types of aggregate. A recently built full-scale wheel trafficker system applies accelerated traffic loading to 1.5 m wide unsurfaced test sections. Accelerometers were installed on the surface to measure changes in the aggregate stiffness with traffic loading using multichannel analysis of surface waves (MASW). This method facilitates non-destructive measurements of stiffness at numerous depths throughout the aggregate. The average shear wave velocity and rutting performance are presented for each soil-geogrid composite.
