Degradation of Exposed LLDPE and HDPE Geomembranes: A Review

摘要

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