Assessment of relative density on shear strength and volumetric characteristics of sand-EPS particulate mixtures

Abdi, Mahmood Reza; Khakbazan, Ali; Kazemi Abyaneh, Maryam; Safdari Seh Gonbad, Mahdi

doi:10.24200/sci.2024.62072.7634

Assessment of relative density on shear strength and volumetric characteristics of sand-EPS particulate mixtures

Articles in Press

Document Type : Research Article

Authors

Mahmood Reza Abdi ¹

Ali Khakbazan ²

Maryam Kazemi Abyaneh ³

Mahdi Safdari Seh Gonbad ³

¹ Civil Engineering Faculty, K.N. Toosi University of Technology, Tehran, Iran

² Water-Soil Department, Imam Khomeini Higher Education Center, Karaj, Iran

³ Geotechnical Postgraduate, Civil Engineering Faculty, K.N. Toosi University of Technology, Tehran, Iran

10.24200/sci.2024.62072.7634

Abstract

Geofoam is widely used in civil engineering projects due to its low unit weight, insensitivity to moisture variations and high erosion resistance. In present study, the effect of expanded polystyrene (EPS) particulates on the shear strength and volumetric characteristics of sand has been investigated using direct shear test. Sand has been mixed with 0.1, 0.2 and 0.3% EPS as dry weight of soil and compacted to relative densities (Rd) of 60, 65, 70, 75 and 80% in a shear box 60×60×26 mm and subjected to normal pressures of 100, 200 and 300 kPa. Results showed that by the addition of geofoam particulates to sand, shear strength characteristics such as cohesion, angle of internal friction and dilation as well as the stiffness of the mixtures decreased resulting in overall reduction of the shear strength. Increasing the relative density of sand-geofoam particulate mixtures, reversed the changes in the preceding characteristics. Shear strength and stiffness of samples improved with increase in normal pressure whereas dilation angles decreased. Cohesions displayed by samples are apparent and attributed to the penetration of sand particles into geofoam particulates resulting in particle confinement and thus reduction of dilation.

Keywords

Direct shear

Sand

Geofoam particulates

Relative density

Dilation