ABSTRACT
High-density (HDPE) and linear low-density polyethylene (LLDPE) geomembranes are used in barrier systems in various containment applications. The former is known for its better chemical resistance, while the latter is known for its higher stress-crack resistance (SCR). The SCR of high-density polyethylene is well defined in the literature, but the SCR of LLDPE as well as its failure mechanism are rarely addressed. This paper thus investigates the SCR of LLDPE versus HDPE geomembranes based on the fractured plane of unaged and aged specimens examined using the single-point notched constant load tensile test method. The GMBs were aged using a synthetic heap leaching solution with pH 13.5 at 85°C. Failed specimens are analyzed using scanning electron microscopy, after which the differences in fracture surface for both LLDPE and HDPE resins are discussed. The relationship between SCR, tensile break elongation, and melt flow index is also presented for the geomembranes examined.
