Ductile-To-Brittle Transition Time in Polyethylene Geomembrane Sheet

The susceptibility of polyethylene (PE) geomembranes to stress cracking was evaluated in the laboratory using an accelerated notched constant load testing (NCLT) method. The test specimens were subjected to various stress levels which ranged from 25% to 70% of the yield stress at 50°C. The ductile-to-brittle failure curves of five different geomembranes were obtained by plotting the logarithm of percent yield stress against the logarithm of average failure time. The stress cracking resistance (SCR) is quantified as the value of the ductile-to-brittle transition time. The results show that SCR of these geomembrane sheets vary over a wide range from a minimum of 4 hours to over 600 hours.