Laboratory Investigation of Critical Factors Affecting Geogrid Reinforcement on Aggregate Base Using Loaded Wheel Tester

Abstract

A modified loaded wheel tester, asphalt pavement analyzer (APA), was employed to evaluate the reinforcement effect of geogrids on unbound granular base course materials by applying simulated repeated wheel loads on the compacted reinforced specimen. Three indicators, traffic benefit ratio (TBR), rutting reduction rate (RRR), and rate of deformation (ROD), were used to characterize the permanent deformation behavior of reinforced aggregate with the number of loading repetitions. Three critical influence factors, aggregate base gradation, geogrid tensile strength, and geogrid aperture geometry, were analyzed for the reinforcement effect. The results show that the inclusion of geogrids in unbound granular base materials could significantly improve their resistance to rutting. A better reinforcement effect could be obtained by increasing the portion of effective aggregates interacting positively with geogrids, increasing geogrid tensile strength. The reinforcement effect of triaxial geogrids was better than that of biaxial geogrids with a similar tensile strength. The geogrid tensile strength had more significant effects on the reinforcement than the aperture geometry.