Dam#Concrete-face rock-fill dams
As a CFR dam or with the short form CFRD a special construction of dams is called. The acronym stands for the English name Concrete Faced rockfill Dam, which can be translated analogously with " rockfill dam with concrete cover ".
Design and production
A CFR dam is first made of a coarse riprap ( rockfill dam). This is followed on the water-side slope of the embankment of the casting of a concrete shell ( concrete face). The concrete surface produced in vertical stripes only receives a light steel reinforcement to prevent cracks ( " crack reinforcement "). The strips may be up to 15 m wide and are concreted using slipforms from the foot to the crown of the dam in one piece, bringing the number of joints is minimized. The unavoidable, vertical joints between the concrete strips are sealed with waterstops. It is, for example, rubber or a corrosion resistant metal, such as copper, are used.
For the water-tight connection of the concrete shell of the Underground seal of the future reservoir CFR dams are equipped with a stove wall that is made of reinforced concrete and is usually equipped with patrols for maintenance and inspection of the seal.
Origin and development
The origin of CFRD principle located in the California Gold Rush, when prospectors built embankments with wooden planks as a seal for water diversion. The wood was later replaced by concrete when the concept was applied to irrigation and hydropower plants. As a driving force in the development of modern CFRDs applies the American Civil J. Barry Cooke.
In the 1960s, began CFR dams to build on a large scale. The bulk material was compacted to increase the stability and the concrete seal first so made in vertical strips, with no horizontal joints. In the following decades the CFRD construction became more popular. Were particular in China and large CFR dams are built.
Currently, the completed in 2008 Shuibuya Dam in China with 233 m height of the largest CFR Dam. The under construction Chang Heba Dam, also in China, will tower over the Shuibuya dam with 240 meters by seven meters after its completion.
List of largest CFR dams
The list takes into account all CFR dams with a height of over 150 m.