LABORATORY EVALUATION OF GEOSYNTHETIC-REINFORCED PAVEMENT SECTIONS

Preliminary experimental and analytical investigations were conducted to evaluate the performance of pavements with and without geotextile or geogrid reinforcement materials. Four pavement sections were tested: one unreinforced section that served as a control and three sections reinforced with either one of two geotextiles or a geogrid. The pavement sections were constructed to model a typical secondary road in Virginia built over a weak granular (silty sand) subgrade material. Loading of the pavement sections was accomplished through the use of a computer-controlled pneumatic system that delivered approximately 55 kPa through a 30-cm rigid plate at a frequency of 0.5 Hz. The resulting displacement of the pavement surface was monitored by an array of linear variable displacement transformers. The performance of each pavement section was evaluated as a function of the applied number of cycles, the resulting surface deflection profile, and the layer deflection profile. It was concluded that geosynthetics can substantially improve the performance of a pavement section constructed on a subgrade soil with a low California bearing ratio. Also the reinforcing mechanisms of geogrids and geotextiles are different.