Laboratory characterization of soft clay mixed with EPS, lime, fly ash, and sodium silicate

The influence of expanded polystyrene foam (EPS) and sodium silicate content on the density and mechanical properties of soft clay mixed with EPS, lime, fly ash, and sodium silicate is investigated in this study using unconfined compressive strength (UCS), cyclic load (CL), and scanning electron microscope (SEM) tests. It was found that EPS can efficiently decrease the density of mixed soil, whereas sodium silicate has no influence on the density. The UCS, elastic modulus, resilient modulus, and maximum dynamic stress first increased and then decreased with increasing sodium silicate content and decreased with increasing EPS content. When the sodium silicate and EPS contents were 6% and in the range 0.5 to 1%, respectively, the density of the mixed soil could be reduced efficiently, and the mechanical properties could be maintained. Based on this, an EPS content of 0.5 to 1% and a sodium silicate content of 6% can be considered optimal. Subsequently, an empirical model between the UCS, EPS content, and silicate content is proposed, which can provide theoretical support for mixed soil engineering applications.