Longevity Evaluation

There are two separate synthetic components to the HydroTurf® System. They are the Engineered Turf and the 50-mil Structured Geomembrane. Longevity predictions for each component under long term exposure have been evaluated.

The synthetic turf technology was originally developed for professional sport venues. Over the last decade the technology has improved significantly. The latest generation of polyethylene turf material provides excellent long term residual strength and color durability against UV light.

For HydroTurf, the engineered turf yarns are the only synthetic component of the system that is directly exposed to the elements, specifically ultraviolet light (UV). Weathering tests of these yarns have been performed in accordance with ASTM G147 and G7 at Atlas Material Testing Laboratories in New River, AZ. Samples were exposed to direct UV facing south at a 45 degree angle. An example of the weathering apparatus is shown in the photograph.

Weathering Apparatus at Atlas Material Testing Laboratories

Photo of Weathering Apparatus at Atlas Material Testing Laboratories

Weathering Apparatus at Atlas Material Testing Laboratories

The samples were exposed for a given period and then the retained tensile strength was measured. Retained tensile strength was plotted against exposure duration as shown in the graph. A logarithmic line was fit and projected out to 1,000,000 hours. At 100 years (876,000 hours), the retained tensile strength of the synthetic turf yarn is projected to be approximately 65%. At 65% retained tensile strength, it will continue to function as designed.

Retained Tensile Strength of Synthetic Turf Fibers vs. Weathering Exposure Duration

Chart showing Retained Tensile Strength of Synthetic Turf Fibers vs. Weathering Exposure Duration

Retained Tensile Strength of Synthetic Turf Fibers vs. Weathering Exposure Duration

The Geosynthetic Institute (GSI) has performed extensive testing evaluations of the longevity of HDPE geomembranes. This research is presented in Geosynthetic Institute, White Paper #6 – “Geomembrane Lifetime Prediction”, February 8, 2011. For an in-situ annual average temperature of 30 degrees Celsius, GSI estimates a lifetime prediction of 265 years for an HDPE geomembrane.

Therefore based on these evaluations, the HydroTurf System will have a 100+ year functional longevity when properly maintained.