ABSTRACT
It is a general practice to recommend high-permeable granular subbase layers in pavements to avoid moisture infiltration into subgrade. In this study, a three-layered pavement was prepared in a large-scale permeameter to estimate the drainage capacity of controlled and geocomposite-embedded subbase layers under realistic traffic loading. Preliminary studies indicate that the measured permeability of subbase layer was 4 m/day, which do not meet the design criteria of 300 m/day. Two types of geocomposites (GCs) viz., bi-planar (2D-GC) and tri-planar (3D-GC) were used to enhance the drainage capabilities. Results indicated that the improved permeability of the subbase was 410 and 725 m/day, respectively, for bi- and tri-planar GCs. The compression of GCs in the subbase layer decreased the permeability up to 40% for 2D-GC and 20% for 3D-GCs for a given load equivalency factors of 0.63 to 2.54. In addition, PLAXIS-2D analysis was performed to confirm the reinforcement function of GCs.
