What is concrete efflorescence?
Efflorescence is a crystalline deposit of salts that can form when water is present in or on brick, concrete, stone, stucco or other building surfaces. It has a white or greyish tint and consists of salt deposits that remain on the surface after water evaporates.
What is concrete weathering action?
Weathering is the effect of pollution and natural forces, such as frost, rain and sunlight, on a structure. This phenomenon is controlled by many factors, including the surface texture of the concrete, the architectural detailing and the orientation of the structure. …
What causes efflorescence in concrete?
Efflorescence is caused by vapor migrating through the slab bringing soluble salts to the surface of the concrete. Efflorescence is normally worn off or washed away on unsealed concrete surfaces. In stubborn cases, a mild acid rinse or even a light sandblasting may be necessary.
What are the 5 structural problems of concrete?
Problems with concrete include construction errors, disintegration, scaling, cracking, efflorescence, erosion, spalling, and popouts.
What is efflorescence example?
In chemistry, an example of efflorescence is when a gypsum is exposed to a dry environment it will lose its water by evaporation and form a solid crust, anhydrite, on the surface. Word origin: Latin efflorescere (to bloom, blossom).
What are the causes of efflorescence?
Efflorescence is caused when soluble salts and other water dispersible materials come to the surface of concrete and mortars. It’s induced by low temperatures, moist conditions, condensation, rain, dew, and water added to the surface of fresh concrete to assist troweling.
What are the failures in concrete?
Below we’ve listed the 5 most common concrete failures that we frequently repair and their causes.
- MECHANICAL. Most mechanical failures occur because of physical impacts such as collisions.
- CHEMICAL.
- FIRE.
- STRAY CURRENTS.
- CORROSION.
What are the defect in concrete?
Different types of defects in concrete structures can be cracking, crazing, blistering, delamination, dusting, curling, efflorescence, scaling and spalling. These defects can be due to various reasons or causes.
What is called efflorescence?
efflorescence, spontaneous loss of water by a hydrated salt, which occurs when the aqueous vapor pressure of the hydrate is greater than the partial pressure of the water vapour in the air.
What is efflorescence give two examples?
Answer: Efflorescence is the loss of water (or a solvent) of crystallization from a hydrated or solvated salt to the atmosphere on exposure to air. The water, with the salt now held in solution, migrates to the surface, then evaporates, leaving a coating of the salt. Example is Gypsum (CaSO4.
What does efflorescence look like on a concrete floor?
Efflorescence is a deposit of soluble salts and bases, usually white in color, that sometimes appear on the surfaces of masonry or concrete construction. Although it may be an aesthetic concern, efflorescence will not affect structural performance. Often efflorescence is apparent just after the structure is completed.
What is the meaning of the term efflorescence?
Efflorescence is defined as the appearance of an unwanted, powdery substance on the surface of concrete or mortar.
What causes white discoloration on the surface of concrete?
Usually this white or off-white discoloration to concrete and masonry forms when soluble salts and other water dispersible materials come to the surface through capillary voids as a result of temperature changes, moist migration, condensation, rain, dew, and/or too much water in the mix.
Why does Portland cement have a lot of efflorescence?
Any material containing portland cement is susceptible to efflorescence. It generally occurs when calcium hydroxide (lime) formed in cement hydration reaction is transported by water to the surface through capillaries in the concrete. There, it combines with carbon dioxide from the air to produce calcium carbonate and water.