Behavior of EPS geofoam as flexible pavement subgrade material in model tests

The behavior of expanded polystyrene (EPS) geofoam used as subgrade and fill material under flexible pavement was investigated by carrying out a series of tests in a model pavement testing facility. In the experimental setup, pavement test sections that consisted of a wearing course, a gravel base layer, and a sand subbase were placed on EPS blocks inside a test tank. Traffic loading on the test pavement was simulated using a loaded wheel running on an oval-shaped test track. The investigation studied the effects of repeated traffic loading on the performance of the EPS geofoam, the influence of the EPS block size, and the presence or lack of lateral restraint. For comparison purposes, a pavement section using sand fill instead of EPS geofoam was also constructed and tested and is considered as the baseline case. The performance of the EPS geofoam was benchmarked against the baseline case to analyze its performance and to determine possible problems that may occur when used in full-scale pavement sections. Implications for pavement design are also discussed.