Compaction and cbr properties of sand mixed with modified waste eps

This research presents the results of the study which influence the use of recycled waste expanded polystyrene foams (EPS), as a lightweight fill material when mixed with river sand. In this study, thermally modified waste EPS have been used. The waste EPS were put in to an oven at 130°C through 15 minutes to obtain modified expanded polystyrene (MEPS). Compaction properties and California Bearing Ratio (CBR) values of sand mixed with MEPS were investigated. For this purpose, five series of compaction tests were prepared that have 0%, 5%, 10%, 15%, and 20% MEPS by weight. Two types of compaction tests were carried out. These are standard and modified proctor tests. From each test results, effect of MEPS on optimum moisture content and maximum dry density was investigated. CBR are tests were also carried out after standard and modified proctor compaction. Tests were performed for unsoaked condition. The results showed that addition of MEPS to river sand decreases maximum dry density with increasing percentage of MEPS for both standard and modified proctor compaction. Optimum moisture content of the mixture was not affected for both tests. CBR values of the mixture were reduced when the percentage of the MEPS increased in the mixture. However, lowest CBR value at 20% MEPS are still within the acceptance limits for sub-base.