"Effect of HDPE geomembrane thickness on the depletion of antioxidants"
M. Zahirul Islam, P.Eng.
PhD Candidate, Dept of Civil Engineering
GeoEngineering Centre at Queen’s-RMC
Queen's University, Kingston
ON, K7L 3N6
This study describes an accelerated ageing test to evaluate the effect of thickness on the depletion of antioxidant from high density polyethylene (HDPE) geomembranes. Three HDPE geomembranes having nominal thicknesses of 1.5, 2.0, and 2.5mm were examined in the testing program. The geomembranes were immersed in a synthetic leachate at four temperatures: 22, 55, 70, and 850C. The depletion of antioxidant was monitored in terms of the oxidative induction time (OIT). It was observed that antioxidants depleted at a faster rate from 1.5mm geomembrane than from the 2.0 and 2.5mm geomembranes. Antioxidant depletion time was predicted using Arrhenius modeling and was found to be longer for thicker geomembranes, which suggests that a thicker geomembrane may be expected to have a longer service life (other things being equal).