Degradation of Exposed LLDPE and HDPE Geomembranes: A Review

Abstract

The service life of geomembranes varies significantly based on their exposure conditions. For instance, the service life of polymeric geomembranes exposed to atmospheric conditions with solar radiation, high temperatures, and oxygen is anticipated to be shorter than that of buried geomembranes. Both linear low density polyethylene (LLDPE) geomembranes and high density polyethylene (HDPE) geomembranes are used for exposed applications (e.g., landfill covers, pond and canal liners, etc.). LLDPE geomembranes are very flexible, with a higher tensile break elongation than HDPE geomembranes and, therefore, greater ability to maintain their integrity under localized differential settlement without puncturing, tearing, or cracking. On the other hand, HDPE geomembranes have excellent ultraviolet (UV) and chemical resistance; however, they have low puncture resistance and low multi-axial extensibility compared to LLDPE geomembranes. This paper compares the relative performance of exposed LLDPE and HDPE geomembranes based on laboratory test results and field performance data.