Strength and deformation characteristics of EPS bead-mixed sand

Abstract

In this research, a study on strength and deformation characteristics of expanded polystyrene (EPS) bead-mixed sand was comprehensively conducted. A series of standard Proctor compaction tests were conducted to determine the proper amount water for use in the mixing between EPS bead and sand at the volumetric ratio of 1:1. A special series of drained triaxial compression tests were performed on the sand-EPS bead mixture (SEM) specimens. Various loading histories, consisting of: i) monotonic loading (ML) at different constant strain rates; ii) sustained (creep) loading (SL); iii) cyclic loading with small strain-amplitude (CL); and iv) stepwise changes in the strain rate during otherwise ML, were employed in this study. These loading histories were used to evaluate the elastic and viscous properties of the SEM. Then these properties were also compared with the ones obtained from the sand alone under similar loading conditions. It is found that the elastic and viscous properties of the SEM are qualitatively similar to those of sand alone. They are different in terms of quantity. A non-linear three-component (NTC) model was used to simulate the elasto-viscoplastic deformations of the SEM. The simulations are well successful by using the model parameters determined especially for the SEM sand under the conventional model framework.