2. Works classification

Concrete structures for storing and transporting water are classified according to how they are sealed.

• Class A: structures whose watertightness is ensured by the structure alone

  These are mainly reinforced and/or prestressed concrete structures, which may be treated with mass or surface waterproofing.

  Apart from variations in volume due to temperature variations and evaporation, leakage must not exceed an average of 500 cm ³ /m ² /day.

  For above-ground basins, this condition can be considered to have been met if there are no apparent leaks or aesthetic defects. A simple stain is not considered to be a leak, as long as it disappears quickly in the days following watering (a stain...