In Situ Measurements of Secondary Road Flexible Pavement Response to Vehicular Loading

Abstract

In June 1994, a secondary road pavement section 150 m long was instrumented in Bedford County, Virginia. This pavement section was composed of nine individual sections each 15 m long. Sections 1 through 3 had a limestone base course 100 mm thick (VDOT 21-B); Sections 4 through 6 had a base course 150 mm thick; and Sections 7 through 9 had a base course 200 mm thick. Three sections were stabilized with geotextiles, three were stabilized with geogrids at the base course–subgrade interface, and the other three were kept as control sections. One section from each stabilization category was included in each base course thickness group. The outside wheel path of the inner lane was instrumented with strain gauges, pressure cells, piezoelectric sensors, thermocouples, and moisture sensors. A Keithley 500-A data acquisition system was used to collect instrument responses on-site. Some of the data collected by the instruments are discussed. Section performances based on the instrumentation response to controlled and normal vehicular loading indicated that geosynthetic stabilization provided significant improvement, which was found to be in agreement with rut-depth measurements.