Durability and lifetime of polymer fibers with respect to reinforced geosynthetic clay barriers; i.e., reinforced GCLs

摘要

This paper describes the physical and chemical degradation of polypropylene and polyethylene fibers that are used in needlepunched and stitch bonded reinforced geosynthetic clay barriers (GBR-Cr) which are generally called geosynthetic clay liners (GCLs). Details of the degradation mechanisms of the fibers and their consequences are discussed based on the presently available literature. The influence of material structure, in particular polymeric orientation and ambient environmental conditions on the degradation are evaluated. In addition, the significance of the antioxidant package in the resin is described. The potential depletion mechanisms of antioxidants in various applications are presented. Possible performance and index test methods, which can be used for monitoring the polymeric degradation of reinforcing fibers are suggested. Such monitoring leads directly to lifetime prediction. Finally, a proposed generic specification is included which incorporates several unique test methods focusing on durability of the components, including the fiber reinforcement.