From the GMA Techline
RE: HDPE liner failures
I am looking for information related to predictions or assessments of liner failures. The lead regulatory agency for an Environmental Impact Statement (EIS) is requesting data on HDPE liner failure assessments associated with geosynthetic covers. Our application is to use HDPE to cover an overburden stockpile with a 2-ft soil cover over the geomembrane. Any assistance would be appreciated.
(Rich | Colorado)
Reply: Your question has many pathways in order to answer … let me try.
- Our lifetime prediction from accelerated lab tests when covered at 20 C is about 550 years.
- Our lifetime prediction from accelerated lab tests when exposed is about 50-60 years in a hot climate.
- Stress cracking has been a problem in the past but specification changes in 2000 (lower density, better resins, and better antioxidants) have essentially eliminated the issue. See GRI GM13 specification information.
- Out-of-plane deformation is low in comparison to other GMs, but if the rate of pressurization is slow the material is equivalent to LLDPE and fPP (it’s about 80% elongation at 1.0 psi/month).
- Small holes from stones above or below the GM are an ongoing construction issue.
- Large gouges from construction equipment are not unheard of … better have good CQC/CQA on the jobsite.