Laboratory and Constitutive Modeling of Critical State Behavior of Rockfill Aggregates Mixed with Polymer

Abstract

Abstract In order to increase the strength and deformation properties of coarse aggregates, the polymer was used as an additive. In this study, a series of triaxial tests were performed to analysis the effect of polymer content on the strength, deformation, and critical state of rockfill aggregates. It is found that the deformation properties are the same for different polymer contents. As the polymer content increases, the peak stress increases, and the volume strain decreases. The addition of polymer mainly led to inducing cohesion in rockfill aggregates while showing a marginal influence on friction angle. The average effective stress, which considered the cohesion of polymer as additional effective stress, was modified. It was observed that the critical state envelopes in q–p′pc and e–p′pc were not much influenced by the addition of polymer. A state parameter is used as a function of void ratio and pressure. A boundary surface model of polymer rockfill aggregates based on the critical state approach was proposed. The performance of the model is demonstrated by the results of triaxial tests. The study shows the model could effectively capture the influence of polymer contents and confining pressures on strength and deformation characteristics of rockfill aggregates.