Product Features
Skidmark Geomembrane™ canal lining is a total system which includes a proprietary compound formulation, the extruded sheet design, canal-ready fabricated panels and specifications for canal preparation and liner installation.
Engineering
Canal lining projects may reguire design by a licensed engineer. The Skidmark Geomembrane™ system can provide engineering assistance.
Panel Fabrication and Field Splicing
Rubber compounds like tire rubber are thermosets and as such can only be spliced by hot vulcanization or with weather sensitive chemical (adhesive) bonding. The unique formulation of Skidmark Geomembrane™ can be easily and effectively thermal welded. Panels can be shop prepared to specified sizes with stiffeners as required. The panels are then delivered to the job site in a size and weight that allows placement by a small number of workers and seams can be welded using an affordable welding tool.
Life Expectancy
The Geosynthetic Institute GRI White Paper #6 discusses the complexities of lifetime prediction of geomembranes. This paper is suggested reading for a better understanding of the many issues that effect canal liner life. Although Skidmark Geomembrane™ has only recently been used as an exposed canal liner, it is reasonable to expect 20 years of service life. This expectation is based on the inert properties of tire rubber (it will not bio-degrade in landfills), the known performance of similar thermoplastics that are used as the rubber binder and the "pass" results of ASTM D 1149-07 ozone resistance test.
Durability
Another suggested reading for anyone responsible for selecting a canal lining geomembrane is, “Optimum Use of Geomembrane Materials in Irrigation Canal Lining.” This article by Dr. Ian D. Peggs was printed in a 2007 ICID newsletter and presents the reader with six basic considerations for geomembrane selection. The article also discusses some of the negative characteristics of HDPE, the most often specified material. Dr. Peggs states that higher strength materials have lower elongations at break therefore have less ability to conform to rough sub-grades. “Ductility in a geomembrane is often a far more important parameter than strength.”
Tire rubber used in the Skidmark Geomembrane™ formulation has been ground to a very fine mesh specification. This provides good physical properties for a recycled rubber sheet. However the best feature of this material is ductility, the ability to undergo change of form without breaking.
Do-It-Yourself or Low Cost Installation
The additional weight of a thicker liner could be considered a negative issue during installation. This has been addressed by installation designs that provide fabricated panels of a size and weight that can be positioned by small crews. Further, shorter panels allow ease of alignment as the liner follows the turns found in many small canals. The shorter panels are made possible by the simplicity of field splicing and the cut-off design.
Geomembrane Cost
The price of oil rose above $150 dollars per barrel in 2008. Geomembranes made of EPDM, HDPE, and PVC rely on petroleum feedstock. Consequently, the supply and costs of these polymers may be unpredictable in the future.
Due to the costs associated with tire recovery and grinding to a premium mesh specification, Skidmark Geomembrane™ is not priced like a recycled rubber truck bed liner or mud flap. However, it is possible to provide a membrane that is much thicker while the cost remains competitive with many exposed geomembrane products available. Considering the number of tires being discarded every year, the raw material supply seams guaranteed.
Important Cost Saving Considerations
The developers of the Skidmark Geomembrane™ system are aware that the responsibility and at least part of the cost of lining a canal is placed on the land owner. The following features were designed with the landowner in mind.
- Canal soil preparation less critical, can tolerate smooth rocks up to 1"
- Liner will not be damaged by foot traffic or light rubber tired equipment used during installation.
- Fabricated panels can be postioned by a small crew of workers
- Field splices can be performed quickly with minimal training using an affordable tool
- Attached stiffeners and liner weight make ballesting unnecessary except in special situations
- Repairs can be made using kits that require no special tools or skills