What is efflorescence?
Efflorescence is a process in which alkaline materials, including lime, become soluble then migrate to the deposit on the surface and dry. These alkaline materials become carbonated from the atmosphere and become crystalline and form white deposits that give an unattractive appearance for architectural pieces. This staining must be removed using labor intensive techniques such as acid washing or sand blasting. MetaMax can help to reduce efflorescence by two methods: 1. MetaMax reacts with the lime to form insoluble, beneficial cementitious products that will not dissolve or deposit on the surface. 2. The reaction of MetaMax with lime forms cementitious materials that help to densify the cement paste and reduce the permeability which will reduce the amount of water migration that would allow the lime to rise to the surface.
A. A white deposit of calcium carbonate on concrete surfaces. It results from the reaction of calcium hydroxide with carbon dioxide from the air. The calcium hydroxide is a byproduct when cement hydrates. It is slightly soluble in water and migrates to the surface through capillary action. The calcium hydroxide remains on the surface, reacts with carbon dioxide, which forms calcium carbonate and water. This conversion, depending on weather conditions, will dissipate over time. Calcium carbonate is the most common type of efflorescence. The presence of efflorescence does not compromise the structural integrity and is not indicative of a flawed product.
Efflorescence is a natural phenomenon caused by the formation of an off-white calcite on the surface of concrete products made with cement. One in the inherent components of cement is construction lime. During the concrete manufacturing process that consists of mixing cement, water, sand, coarse aggregate and chemical auxiliaries, a series of chemical reactions occur and result in the formation of a solid material: concrete. Construction lime is released during these reactions and migrates through a micro porous network towards the surface of the concrete when it is wet. This lime, once in contact with the carbonic gas present in the air, is transformed into calcite. This phenomenon is efflorescence. The efflorescence will disappear on its own after two or three years of exposure to weather stress but it is possible to eliminate it more rapidly by cleaning the concrete product with the appropriate detergents.
Efflorescence is a white haze that may appear on the surface of concrete pavers after a few weeks or months. Efflorescence is completely natural and will disappear with time. Your products are not damaged or defective. Efflorescence is produced by cement, which is a necessary ingredient in all concrete products.
Efflorescence is a natural occurrence in some concrete pavers. As the pavers dry out after manufacturing – something they will do for some time – water migrates to the surface through capillary pores, carrying with it calcium hydroxide. The calcium hydroxide is a result of water reacting with the free lime in cement products. All concrete products contain cement and lime is a key ingredient in cement. The resulting white residue, or calcium hydroxide, found on the surface of some pavers will eventually dissolve in the presence of rainwater and carbon dioxide, but it may take from 3 months to a year in some concrete products. This process is accelerated in climates featuring frequent rain followed by sunny days. Conversely, the process will take longer in drier climates.
