ABSTRACT
High-density polyethylene geomembranes (HDPE GMBs) are in-situ welded to create an “impermeable seal”. Extrusion welds are primarily used for repairs, curves, and other welds not accessible to fusion welding machines. A welding rod which is fed into the extrusion machine is made from the same raw materials for adherence/compatibility requirements between the two materials. The examined geomembrane was welded using preheat and barrel temperatures of 230°C and 250°C, respectively. In a municipal solid waste (MSW) landfill, an extrusion weld facing upward will be in contact with leachate that can lead to chemical degradation. In this paper, the antioxidant depletion rate from welding bead and HDPE GMB sheet away from welding immersed in MSW landfill simulation is examined over an 11-month period at 85°C, 75°C, and 65°C. Preliminary results shows that antioxidant depletion rate of the welding bead was faster than that for the GMB sheet material at lower temperatures (i.e. 65°C)
