Mechanical properties of SCA modified EPS lightweight soil and modification mechanism Available to Purchase

Expanded Polystyrene (EPS) granular lightweight soil (ELS) is an eco-friendly material made of EPS particles, cement, soil, and water. This study investigates the modification of ELS using a silane coupling agent (SCA) solution to improve its performance. Various tests were performed, including flowability, dry shrinkage, unconfined compressive strength (UCS), triaxial, hollow torsional shear, and scanning electron microscopy (SEM) analysis, to evaluate the physical and mechanical properties at different SCA concentrations. The results show that the optimal SCA concentration was 6%, improving flowability by 13% and increasing dry shrinkage weight by 4%. The UCS increased with SCA concentration, reaching 266 and 361 kPa after 7 and 28 days, respectively, at 6% SCA. Triaxial and shear tests indicated improved shear strength, with the maximum shear strength reaching 500 kPa, internal friction angle rising by 4%, and cohesion reaching 114 kPa at 6% SCA. Hollow torsion shear tests showed that 6% SCA enhanced stiffness and resistance to deformation, while reducing the non-coaxial effect. SEM analysis revealed that SCA strengthened the bond between EPS particles and the cement matrix, improving the interfacial bond. This study highlights the potential of modified ELS for sustainable construction.