Laboratory Characterization of Reinforced Crushed Limestone under Monotonic and Cyclic Loading

Abstract

A series of triaxial compression tests and cyclic triaxial tests were conducted on unreinforced and geogrid reinforced crushed limestone samples to investigate the effects of the geogrid type, location, and number of layers on the strength, stiffness, and cyclic deformability of these samples. Five different types of geogrids were used. For each geogrid type, four different reinforcement arrangements were investigated. Comprehensive statistical analyses were conducted on the collected triaxial test data. The results of these analyses indicated that the geogrid inclusion within crushed limestone samples increased significantly their elastic modulus and ultimate shear strength, while it reduced their permanent deformation; thus, the geogrid is expected to enhance the performance of base course material in the field and reduce its deformation. The results also showed that stiffer geogrids exhibited greater improvement. Moreover, samples reinforced with two geogrid layers placed at the upper and lower third of the sample height always had the highest improvement, while the lowest improvement was observed for samples with a single geogrid layer placed at the sample’s midheight. Finally, the results demonstrated that the geogrid did not have a significant effect on the resilient behavior of the crushed limestone samples.