Elements, which placed on the reinforcements:

Ensure their immobility during concreting

Guarantee the coating

Described as:

Elements made of resistant materials (concrete, mortar, rigid plastic or similar material).

They do not induce corrosion in the reinforcements.

Impervious to water such as concrete and resistant to chemical attacks they may be subjected to.

If they are made of concrete, these shall be, in terms of resistance, permeability, hygroscopicity, thermal expansion, etc. of a verifiable quality to that used in the construction of the piece.

If they are made of a material that does not contain cement (rigid plastic for example), they must have holes with a total section at least equivalent to 25% of the total surface area of the separator, to ensure their good link with the concrete of the piece.