Properties and Applications of Cement-Treated Sand-Expanded Polystyrene Bead Lightweight Fill

Abstract

To mitigate settlement problems associated with bridge approach embankments over soft soil, a newly-developed lightweight material was proposed in this study. This lightweight material consisted of expanded polystyrene beads, the hydraulic sand from the Yangtze River, and cement. The mechanical properties of the mixed lightweight material were determined through a series of laboratory tests, including standard Proctor tests, unconfined compression tests, California Bearing Ratio (CBR) tests, unconsolidated-undrained tests, and consolidated-undrained tests. The laboratory results showed the favorable properties of the lightweight material and that it can be used as a backfill material in highway embankment projects. A field study was also conducted to verify the performance of the embankment backfilled with this lightweight material, which resulted in a smaller settlement than the embankment backfilled with lime-stabilized soil (with and without any other ground improvement). Sand cone and CBR tests were performed in the field to verify the density and strength/stiffness of the lightweight fill.