Sulfate attack can be ‘external’ or ‘internal’. External: due to penetration of sulfates in solution, in groundwater for example, into the concrete from outside. Internal: due to a soluble source being incorporated into the concrete at the time of mixing, gypsum in the aggregate, for example. External sulfate attack This is the more common type(…)

Sulfate attack is a chemical breakdown mechanism where sulfate ions attack components of the cement paste. The compounds responsible for sulfate attack are water-soluble sulfate-containing salts, such as alkali-earth (calcium, magnesium) and alkali (sodium, potassium) sulfates that are capable of chemically reacting with components of concrete. Sulfate attack might show itself in different forms Depending(…)