Concrete is nowadays the most widely used building material. Its composition influences its characteristics.
The choice will depend on the building site nature and the type of concrete to be used, which is segmented in several exposure classes :

Curent classes of exposure:

. X0 = No risk of corrosion or attack.
. XC = Corrosion induced by carbonation – Reinforced concrete.
  XC1 = Surfaces under long-term water contact ; exterior walls protected from the wet ; floors and interior walls.
  XC1/XC2 = Shallow foundation.
. XF = Risk of freezing / de-icing – Reinforced concrete.
  XF1 ou + : Non-protected exterior walls.
  XF2 ou XF4 : Freeze / thaw with or without de-icing agents.

Particular classes of exposures:

. XD ou XS = Corrosion of reinforcement by chloride penetration – Reinforced concrete.
  XD2 : non-marine chloride, wet, rarely dry.
  XD3 : non-marine chloride, cyclic wet and dry – ramps and concrete slabs of covered parkings.
. XS1 (XS2) = Exposed to marine chlorides, to airborne salt but not in direct contact with sea water.
. XS2 = Marine chloride, element of a marine structure constantly submerged.
. XS3 = Marine chloride, drowndown zone, exposed to water projection or sprays
. XA = Chemical attack – Reinforced concrete.

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Fibre reinforced concrete is a material composed by fibres which are added to the concrete composition.
There are several kinds of fibres: metal, organic, ceramic and its impact on concrete can change according to :
- Bending and ductility resistance: fibres improve concrete ductility, concrete can change form without breaking.
- Fatigue resistance: fibres make concrete more resistant in the long run and avoid it from cracking.
- Abrasion resistance: this is a wearing phenomen caused by repeated friction, which can crack the material. The addition of the fibres into the concrete improves the abrasion resistance and avoid the cracking.

The fibre reinforced concrete we use is composed by organic fibres, polypropylene, which allows to reduce young cracking, it improves workability and allows a smooth surface finishing.

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Waterproof concrete has the same basic components that classic concrete in which an adjuvant is added that offers waterproofing characteristics.