Experimental Study on Geotechnical Properties of Clay Soil with Adding Expanded Polystyrene Material

Recently, traditional inert materials were replaced with waste materials, as a contribution to sustainability and waste reduction, as well as development, by providing low-cost and easily accessible materials for Geotechnical soils. Expanded Polystyrene EPS is a kind of lightweight material which has a low density, high compressibility, good chemical, water resistance and ease of use. Non-traditional lightweight materials have been widely used in Geotechnical engineering projects in recent years. Lightweight materials are used to lower vertical and lateral earth pressures. They can also be used as a compressible inclusion behind a retaining wall, as well as lightweight fill in slopes or embankments. An experimental investigation has been carried out in the laboratory. Clay soil with EPS contents of 0.0%, 0.25%, 0.5%, 0.75% and 1%. The tests performed include two of the most important tests in studying the geotechnical properties of reinforced soils. Standard Proctor test, the Unconfined Compression test. The results show that adding EPS chips reduce the weight of the soil as well as the unconfined compression strength UCS. EPS-chip specimens, on the other hand, tended to reach their peak strength at higher strains. Microstructure analyses reveal that with an increase in the content of EPS, the number of pores/vacuums increases, which leads to increases in the optimum moisture content and a decrease in the maximum dry density. Also, with an increase in the content of EPS, the characteristic of the dispersion is dominant in fabric, thus it is less resistant to external loading, and this clearly appears in the unconfined test results.