Optimum Properties of Geocell Reinforcement for Sustainable Low-Volume Paved Roads

Geocells are three-dimensional honeycomb-like geosynthetic structures filled with available geomaterials that vastly improve shear strength of those materials. Geocells provide a possible viable solution for thinly paved roads that use marginal infill geomaterials. The objective of this study was to find an optimum geocell design that utilizes various infill materials and a thin hot-mix asphalt (HMA) overlay. To achieve this study objective, four pavement test sections were constructed at the accelerated pavement testing (APT) facility of the Civil Infrastructure System Laboratory at Kansas State University. Three out of the four lanes contained geocell-reinforced bases with three individual infill geomaterials: crushed limestone, quarry by-products, and recycled asphalt pavement. The fourth test lane, the control section, consisted of a crushed stone base. All sections were heavily instrumented. Repeated loads (80 kN, single axle) were applied using an APT load assembly. Sections with an HMA layer of 50 mm reached the failure criteria of a 12.5 mm rut depth after 10,000 passes due to excessive stress in the subgrade. Redesigned sections with HMA overlay of 100 mm carried more than 1,000,000 passes. Numerical simulation of the APT tests was done using the finite element model. The optimum infill geomaterial property, geocell height, and overlay thickness were obtained from this simulation.