ABSTRACT
Geomembranes sheets used in fluid containment applications are welded together in situ using a dual track hot wedge welder or extrusion welding. In dual track wedge welding, overheating can occur in the weld and still meet typical acceptance standards based on peel and shear strength. However, this overheating depletes antioxidants and contribute to a potential reduction in the service life of the geomembrane in the heat-affected zone (HAZ) and junction zone (JZ) adjacent to the weld. This study examines the relationship between the welding quality and thickness on the production of the weld and any reduction in standard oxidative induction time (Std-OIT) for four HDPE geomembranes. The paper describes ageing tests being conducted on these different welds to evaluate the impact of ageing on the rate of antioxidants depletion during welding on the aging of the junction zone relative to the parent material.
