Performance Evaluation of Pavements Constructed on EPS Geofoam Backfill Using Repeated Plate Load

Abstract

EPS Geofoam is introduced as a suitable material for reducing dead loads and alleviation of settlements in road pavements constructed over poor ground conditions. It has been used successfully in many projects since its appearance in 1960’s, yet, there are still pitfalls regarding its application and design, requiring deeper investigations. A serious problem is related to insufficient functionality of such backfills in preventing ruts on the pavement surface. In this paper, results of a series of cyclic plate load tests are presented, describing the influence of soil thickness, as an influential factor, on the performance of these embankments. Nevertheless, this thickness is not an independent factor. It is also dependent on the density of EPS in the subsequent layers. In practical applications, two layers of EPS with different densities are used and the density of the bottom layer should be minimized in order to reduce overall cost of the pavement along the highway. It has been observed that improper thickness for upper EPS layer (less than 200 mm) significantly reduces the ability of such pavements to tolerate against rutting when a noticeable number of cycles of loading is applied.