Paper Title
Effect of High Density Polyethylene on Engineering Properties of Clay

Abstract
This study investigates the effect of high density polyethylene (HDPE) on the geotechnical properties of low plasticity clay (CL). Commercial HDPE product was mixed at different percentages of dry weight of the soil (1, 3, and 5 %) and the polymer-treated samples were compacted at their maximum dry densities (MDD) and optimum moisture contents (OMC). A comprehensive experimental work was carried out in order to determine the compaction characteristics, permeability coefficient (K), Atterberg limits, and unconfined compressive strength (UCS) of natural and polymer-treated samples. The results revealed that the MDDs of 5% HDPE-treated samples were declined from 17.52±0.015 to 15.62±0.07 KN/m3 and a linear regression (R2= 0.92) was found at increasing the HDPE content from 0 to 5%. Also, the OMCs of polymer-treated samples were significantly decreased with increasing the content of HDPE. Moreover, the UCS of the treated samples was linearly increased (R2= 0.91) with increasing the HDPE contents from 0 to 5%. In contrast, the plasticity index (IP) of natural soil dropped from 16.99% to 9.34% with addition of 5% HDPE. While at 5% HDPE, the permeability coefficient of soil obviously maximized from 0.86E-05± 0.71 to 2.14E-05 ±0.01 cm/s compared to the natural samples. Keywords- Low Plasticity Clay, Polyethylene, Atterberg Limits, Permeability.