What is ESCR (Environmental stress crack resistance) in the geocell datasheet?
The geocell is made of HDPE sheets welded together. In the case of polyethylene, environmental stress cracking is a concern because poor ESCR can cause cracks in the cell sheet, resulting in failure to achieve the desired reinforcement.
Academically, environmental stress cracking refers to the cracking of materials that occurs under the synergistic effect of environmental factors and stress factors. There are three common causes of cracking, solvent crazing, thermal stress cracking, and oxidative stress cracking. Among them, thermal oxidation causes the most obvious reduction in performance. Therefore, when extruding the cell sheet, our company added different doses of antioxidants and ultraviolet absorbers to improve its deficiencies according to customer needs.
Engage in the production and sales of geosynthetics for many years, and the common ESCR index of geocell in the market is ESCR≥5000 hours as per ASTM D1693, for example, Presto Geoweb, Strata Strataweb, and so on.
The ESCR EGS Geosolutions can be as follows: ESCR D1693 ASTM ≥5000 hours ESCR D1693 ASTM ≥4000 hours ESCR D1693 ASTM ≥3000 hours ESCR D1693 ASTM ≥1500 hours
Which one ESCR should I choose?
Different areas are subject to different construction environments. For example, in tropical regions of Africa, high latitude, and high cold regions, we recommend the use of a higher ESCR index. In some regions with a mild climate and no drastic temperature change, an ESCR of 3000 to 4000 is also acceptable. Of course, if you have enough budget, it’s best to choose a geocell with a high index.
All such failures in HDPE Sheet occurred when the Sheet had been exposed to continuous processes of UV light, high-temperature oxidation, and/or low-temperature contraction. Therefore, during the construction of the geocell, long-term exposure should be avoided to reduce environmental stress cracking.