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Laying down the first accropode

1er juillet 2014

The Regional Council, as well as the French State and the European Union launched the construction work of the New Coastal Road, with the symbolic laying of the first accropode. This element is essential for the construction of the protective shell in the construction of modern dikes.

For the New Coastal Road, 20,000 blocks will be used to construct the dikes and the junction of La Possession. Their main function is to disperse the sea swell in order to protect the road. Several types of blocks will be used : X blocks, grooved cubic blocks and Type II Acropodes. These elements of the infrastructure are protected by patents (except for the cubic grooved blocks) and the holder of the patent provides the diagram for the formwork, the installation plan and monitors installation. The forms (which vary, depending on the type of block) and the blocks themselves are manufactured in Reunion using local materials (sand, gravel, water etc.).

Technical details concerning types I and II :
A pioneer of single-layer technology since its creation in 1981, the ACCROPODE ™ technique has become a world reference for the protective shells of modern dikes.

Protective shells, referred to as single layer, that protects dikes vulnerable to sea swell, are made up of non reinforced concrete, specifically created with the aim of being laid down in a single layer. Experience shows that this type of protective shell is as effective as the two layer classic systems, while remaining less expensive. Invented in 1981 by Sogreah Consutants (SOGREAH) in France, the ACCROPODE ™ technique was already based on detailed research and considerable experience acquired from the Tetrapode Block invented by SOGREAH in 1952.

On the basis of the experience obtained from a large number of projects, the form of the ACCROPODE ™ was improved to create the ACCROPODE ™ II. Invented and patented by SOGREAH in 1999, for particularly vulnerable sites and particularly difficult installation conditions, its industrial development was finalised in 2003-2004. The ACCROPODE ™ II is distributed by CLI (Concrete Layer Innovations), a subsidiary of Sogreah Consultants.
The new form of the ACCROPODE ™ II is a development based on the form of the ACCROPODE ™ Block, based on accumulated experience from all the CLI Blocks. The wide flat surfaces, as well as the right angles, have been replaced by smaller surfaces and a large number of chamfers. In addition, the general shape of the block has been redesigned in order to improve the following aspects.

  • > Hydraulic performance of the protective shell ;
  • > Structural integrity of the block ;
  • > Construction methods.