Artificial Eco Reefs
Corrosion Free Precast Concrete
Artificial reefs are becoming more common throughout the world, be it for bio-habitats or coastal protection. Commonly, precast concrete elements are used which can be fabricated to suit the intended purpose. One such example, in Propiano at Capo Lauroso, is an artificial reef measuring some 1,100 m in length, submerged at a depth of 35 m, which forms part of the purification station for the Communes du Sartenais Vilinco local authority.
Constructed nearly 10 years ago, it is made up of 45 weights (4 tonnes each) and 15 protective reef elements (10 tonnes each), which have been specially designed to protect a trawling area and to provide a natural habitat for local marine species. The “ecoreefs” are made up of 4 plates, each measuring 3 metres in diameter, stacked on top of each other and supported on three feet, with small walls cast into each plate so as to create numerous habitats on each piece of reef. Each of the facing surfaces have been given a roughened appearance, either by means of being poured into a mould with an irregular inner surface, or by having been given a coating of sand made from crushed shells.
Normally made with steel, the design of these elements called for the removal of all reinforcing and linking steel and having it replaced with BarChip synthetic fibres and glass fibre rods being used as connectors between the elements. “These two materials add significantly to the durability of the construction,” explains Frederic Martarece, Director of International Business and Technical Developments at Bec Freres.
By replacing all steel with non-corrosive reinforcement options the risk of corrosion is completely eliminated, significantly increasing the life of the structure when submerged in a marine environment. Furthermore, the use of BarChip synthetic fibre allows for unique element design that could not be reinforced with traditional steel elements.