In this study we investigated the possibilities of using recyclable fine and coarse grain waste obtained by grinding Polyethylene
Terephthalate (PET) containers, as light filling materials for different applications (clay dams, highway embankments, and backfills
behind retaining structures. Various geotechnical tests were performed on clayey soil and soil-PET mixtures using recycled fine
and coarse granules of Polyethylene Terephthalate bottles. The results indicated that the use of the recycled polymer mixed with
clayey soils as a filling material is favorable for soil properties. The compaction test results indicate that the optimum dry densities
of PET-soil mixtures are less than the optimum dry density of typical soils including the clayey soil used in this study (varying
between 13.83 kN/m3 and 12.55 kN/m3). P-wave velocities values were correlated for PET mixtures. The results indicate that data
concerning the dependence of P-wave velocity values and PET mixtures percentage can be correlated with a coefficient of
determination between R2=0.93 to R2=0.73. Finally, the results show a good potential for using the PET waste as lightweight fill
material.