Experimental Investigation of Shear Strength Behaviors of Stone Dust–EPS Geofoam Interface

Abstract

The stone crushing industry has doubled in size in India in the last decade because aggregate has been the most useful raw material for various structures. However, during crushing of stone aggregates in quarries, huge amounts of stone dust get generated as by-products at every quarry site, which raises the problems of safe disposal and can cause environmental hazards. The proper utilization or environment-friendly disposal of this stone dust is of concern. In this paper, a series of experimental studies were performed to investigate the interface shear strength property of expanded polystyrene (EPS) geofoam to stone dust and geofoam to geofoam using direct shear testing in dry and wet conditions. In addition, the internal shear strength behaviors of unit geofoam blocks were investigated through direct shear tests in dry and wet conditions. In order to examine the effect of density on the interface shear strength behaviors, three different densities of geofoam (12, 15, and 2 kg/m3) were used. The effect of stone dust layer thickness and normal stress on the interface shear strength behaviors were also investigated. The test results revealed that the density of geofoam does not have a significant influence on the EPS/EPS and EPS/stone dust interface strengths. The submergence slightly decreased the EPS/EPS interface strength compared with that in dry conditions for the same density and normal stress level, whereas its effect was found to be much lower on EPS/stone dust interface strength.