Notched Constant Tensile Load (NCTL) Test for High-Density Polyethylene Geomembranes
The notched constant tensile load (NCTL) test, is reintroduced to evaluate the stress-cracking performance of high-density polyethylene (HDPE) geomembranes.
It is mainly applicable to the high-density polyethylene (HDPE) geomembranes used on the landfill site. Dumbbell shaped notched test specimens from a polyolefin sheet are subjected to a constant tensile load in the present of a surface-active agent and at an elevated temperature at 50°C.. The time to failure of test specimens is recorded and the results of a series of such tests conducted at different stress levels are presented by plotting stress level against failure time for each stress level on a log-log axis.
The method has been proposed to ASTM and is being considered by a task group within Committee D-35 on Geosynthetics.