ABSTRACT
Nine instrumented flexible pavement test sections were constructed in a rural secondary road in southwest Virginia. The 15.25 m long test sections were built to examine the effects of geogrid and geotextile stabilization. Three test sections were constructed using a geogrid, three with a geotextile, and three were non-stabilized. The test section base course thicknesses ranged from 10.2 cm to 20.3 cm and the hot-mix asphalt (HMA) thickness averaged 8.9 cm. Geosynthetic stabilization was placed on top of the subgrade layer. An extensive instrumentation infrastructure was constructed to place all instrumentation, cabling, and data acquisition facilities underground.
The pavement test sections were heavily instrumented with two types of pressure cells, soil and HMA strain gages, thermocouples, and soil moisture blocks. In addition, strain gages were installed directly on the geogrid and geotextile. Instrument survivability has ranged from 6% for the strain gages mounted on the geotextile to 100% for the soil moisture blocks after eight months of operation. The majority of instrument failures occurred either during construction or in the first few weeks of operation.
The data acquisition system is triggered by traffic passing over piezoelectric sensors and operates remotely. The data collected is transferred via modem to Virginia Tech for processing. It is planned to monitor the performance of the pavement test sections for a minimum of three years.
