Instrumentation Response of Full-Scale Multi-axial Geogrid Stabilized Flexible Pavements

Full-scale testing of instrumented pavement sections was used to provide pavement response data comparing the performance of multi-axial geogrid stabilized flexible pavement sections to a thicker unstabilized flexible pavement section. Two test items containing different multi-axial geogrids were constructed and trafficked with a dual-tandem axle gear configuration simulating typical highway loadings using ERDC’s Heavy Vehicle Simulator (HVS). Earth pressure cells, single-depth deflectometers, and asphalt strain gauges were embedded in each test item to measure pavement response at critical locations within the pavement structure. Instrumentation response data were collected at designated traffic intervals and compared to the response data from a previously constructed unstabilized flexible pavement section that included an additional 50 mm of crushed aggregate base and an additional 25.4 mm of hot mix asphalt. Subgrade and base pressure cell response values in the stabilized sections were found to be generally equivalent to measured responses in the thicker unstabilized section. Additionally, measured subgrade deflections in the stabilized sections was found to be approximately ½ of that observed in the thicker unstabilized section. The instrumentation response data indicate that incorporation of a multi-axial geogrid in a flexible pavement base course provides improved pavement response and a significant structural benefit.