Concrete products become white in color, which is a result of occurring harmless white powder. That powder usually contains insoluble in water calcium carbonate, which remains on the surface of concrete. It comes into being during the process of bounding concrete as a result of calcium hydroxide and carbon dioxide (present in the air) reaction.
Efflorescence is not a result of poor quality cement or concrete application. Presence of efflorescence impacts aesthetic features of a product, while it does not affect in any negative way the quality of the surface usage.
Over a period of use, sparingly soluble calcium carbonate CaCO3, in the result of reaction with carbon dioxide found in the air, converts into easy soluble in water potassium bicarbonate, which after some time is washed out by rain and undergoes abrasion during the use of the surface.
Requirements provided for in the norm PN-EN 1338 – concrete paving stones permit occurrence of calcium efflorescence as a natural component of concrete maturing process. The norm includes a following wording: “Possible efflorescence does not affect in a negative way performance of pavers and is deemed of no importance”.