Compaction and Strength Characteristics of Modified Waste Expanded Polystyrene (EPS) Mixed with a Standard Sand

This paper presents the use of recycled waste expanded polystyrene (EPS) foams, as a lightweight material with a Nigerian standard sand (Igbokoda sand). Thermally modified waste EPS tagged modified expanded polystyrene (MEPS) was used. The influence of MEPS on compaction characteristics such as the maximum dry density (MDD) and the optimum moisture content was investigated with three different compaction energies: (standard proctor, modified proctor and West African compaction method). MEPS was added to the Igbokoda sand at 1%, 2%, 3%, 4% and 5% by dry weight of soil. The unconfined compressive strength increased from 95.0 kPa to 128.0 kPa, which shows about 34.7% increase in strength with the addition of 5% MEPS. The 5% MEPS content at standard proctor compaction is recommended for sand-MEPS utilization as light weight construction material since it has the lowest MDD, the highest increase in strength and a high value of co-efficient of determination (R² = 0.976). The sand-MEPS mixture can be offered as a potential geotechnical construction material as lightweight backfill for retaining walls, fill in embankments, road sub-base over compressible soil to minimize settlement and simultaneously solving the environmental problem by the beneficial reuse of municipal solid waste (MSW).