Improvement of Engineering Properties of Igbokoda Standard Sand with Shredded Polyethylene Wastes
Geotechnical tests were carried out on sand samples to determine important properties of sand modified with strips of high density polyethylene (HDPE) waste. Strips sizes of 15x20 mm, 20x25mm, 25x30mm were used at concentrations of 1%, 2%, 3%, 4% and 5% by mass of the soil sample. Direct shear test results indicate that with the addition of shredded polyethylene, the shear stress value increased from 4.29kN/m2 to a maximum value of 8.21kN/m2 (a percentage increase of 68.54%) while the angle of internal friction of the sand increased from 18˚ to a maximum value of 28˚ (a percentage increase of 55.56%). The coefficient of permeability “k” reduced with increasing strip size and strip concentration thereby modifying the hydraulic property of the sand from a fine sand range (1.30 x 10-5m/sec) to a silty sand range (4.95 x 10-6m/sec). The permeability test result further shows a direct relationship between the increasing shredded polyethylene sizes and a reduction in the permeability of the soil.