Unit weight of MEPS used in the test was 245 kg/m3 . The maximum dry density of well graded sand was 1,907 and 2,200 kg/m3 for standard and modified proctor tests respectively. Optimum moisture content of the sand was determined to be 14 and 9 % respectively for standard and modified proctor tests. After mixing MEPS with the sand at percentages of 5, 10, 15, and 20, change in maximum dry density and optimum moisture content were investigated. Standard and modified compaction curves for different percentage of MEPS are shown in Fig. 4.