Principal Investigator: Jie Han
Asphalt pavements deteriorate with traffic (especially heavy trucks) and time. Maintenance and overlaying may solve minor to medium pavement distress problems. When the condition of a pavement becomes badly deteriorated, reconstruction of the pavement may become an economic and feasible solution. Reconstruction of a pavement requires removal of pavement surfaces. On-site use of recycled asphalt pavement materials has obvious benefits from economic, to environmental, to sustainability points of view. One attractive option is to use recycled asphalt pavement (RAP) materials as base courses with a thin new overlay. However, RAP has its limitations; for example, it creeps under a sustained load due to the presence of asphalt binder. A preliminary study conducted by the principal investigators has shown that the use of geocell to confine RAP minimizes creep of RAP under a sustained load. However, the performance of geocell-reinforced RAP as a base course overlaid by an asphalt surface is unknown. This research will utilize the geotechnical test box available at the University of Kansas to simulate the reconstruction of damaged asphalt pavements by geocell-reinforced RAP bases overlaid by a thin asphalt layer and evaluate their performance under cyclic loading. The main objectives of this research are to confirm the concept of using RAPs with geocells to reconstruct damaged pavements by heavy trucks and examine the benefit of geocells to the pavement life as compared with unreinforced base courses. In this research, at least four test sections will be constructed in the geotechnical test box including control sections and geocell-reinforced sections. The properties of RAP including asphalt binder content and viscosity, aggregate properties, compaction curve, and California Bearing Ratio (CBR) will be evaluated in the laboratory. The subgrade will be prepared using an artificial soil by mixing Kansas River sand with Kaolin and compacted at an intermediate strength (i.e., 5% CBR). The pavement sections will be tested under cyclic loading up to 25-mm rut depth.