Benefits

Installation of the CARPI system on dams achieves the following:

• Continuous waterproofing of the upstream dam face, including expansion and construction joints and cracks
• A new continuous face drainage system
• A barrier to water infiltration in the event of formation of new cracks
• Reduction of uplift
• Dehydration of the dam body
• Protection from freeze-thaw cycles
• Protection from pure or sulphonated water
• Protection of the dam body in case of alkali-aggregate reaction
• An intervention that does not alter the structure of the dam
• An intervention that is environment friendly, no large construction equipment, no pollution
• An intervention that can be accomplished underwater, thus minimizing impact on dam operation and on the environment.

Durability and Performance

All elements of the system are designed to guarantee > 50 years service in sections permanently exposed to water.

Accelerated aging tests in the laboratory showed SIBELON®, the impermeable synthetic geocomposite developed by CARPI, to have a service life measured in hundreds of years. Those results were further confirmed by laboratory testing conducted on samples of SIBELON® liners exhumed from more than a dozen installations dating back to 1970. Additional testing is ongoing that continues to confirm lifetime exceeding 50 years.

The CARPI system is a well established dam waterproofing system because of its proven:

• Durability which prolongs dam life by decades
• Modular design resulting in quick installation in all climates and simple mob/demob
• Adaptability to rough subgrade reducing installation time and costs and
• Effective waterproofing which dehydrates the dam and arrests deterioration.

Installations have varied from medium height dams to dams exceeding 190 meters, from alpine to the equator, from heavy ice exposure to high ultraviolet exposure, with all installations still performing. Owners, designers and contractors have provided written recommendations testifying to the dependability, longevity, and low maintenance costs associated with the CARPI system. Our system has more than 3,100 cumulated years of service life with owners experiencing zero repair costs.

References

The following are technical publications discussing the CARPI system:

• International Commission on Large Dams (ICOLD), Bulletin N. 78, Waterproofing Geomembranes for Dams,
• ICOLD N. 107, Concrete Dams - Control and Treatment of Cracks,
• ICOLD N. 135, Geomembrane Sealing Systems for Dams, and
• Research Institute of Hydro-Québec (IREQ), IREQ-95-326, Study of Waterproofing Revetments for the Upstream Face of Concrete Dams.

In 1995, the US Army Corps of Engineers Waterways Experiment Station awarded a research project to CARPI to develop an adaptation of the CARPI system to underwater installations. The two-phase project demonstrated feasibility of underwater installation (Technical Reports REMR-CS-50 and 51). In 1997, a full underwater installation of the CARPI system was accomplished on Lost Creek dam in California. The project received several awards:

• 1998 West Region Award of Merit by the Association of State Dam Safety Officials (ASDSO),
• 1999 Hydro Achievement Award for Technology Solution from the National Hydropower Association,
• 1999 Federal Laboratory Consortium Award of Merit from the U.S. Army Corps of Engineers, and
• 2000 International Geosynthetics Society (IGS) Award.

Since 1970, CARPI has successfully installed the CARPI system on more than 125 dams in Africa, Asia, Australia, Europe, North America and South America. The flexibility of the system has allowed intervention on all types of dams at widely varied altitudes and latitudes, including extremely aggressive environments and underwater.