No abstract

A full-scale test section was constructed and trafficked by the U.S. Army Engineer Research and Development Center to evaluate the performance of geosynthetic reinforced aggregate road sections constructed with marginal base materials over a typical subgrade. Eight instrumented aggregate road sections–-including three different aggregate base materials and two different geosynthetics–-were constructed. The mechanistic response and permanent surface deformation of each pavement section were monitored at selected intervals during trafficking, and the data were analyzed to determine the benefit of using geotextiles or geogrids to reinforce aggregate roads. The test section's results indicated that the geosynthetics improved the performance of the reinforced pavement sections compared with unreinforced sections for all aggregate base materials. The mechanistic response in terms of surface deflection, deflection at the top of the subgrade, and vertical stress at the top of the subgrade was favorably consistent with the observed permanent deformation of the individual test items.

A laboratory research program designed to investigate geotextile and geogrid reinforcement of the aggregate layer in unbound pavement sections was performed by the U.S. Army Engineer Research and Development Center. The investigation's objective was to evaluate the performance of geosynthetic-reinforced aggregate road sections over a very soft subgrade. Standard construction materials were used to construct six aggregate road sections in a large steel box. Each instrumented road section was subjected to cyclic plate load tests to evaluate the performance of the model pavement sections under simulated truck traffic. The mechanistic response and permanent deformation of each instrumented pavement section were monitored periodically during each test. Analysis of the experiment data indicated that the geosynthetics improved the performance of the reinforced pavement sections compared with the unreinforced section in terms of improved load distribution and reduced permanent deformation or rutting. Additional information regarding the reinforcement mechanisms is summarized.