Vibration of self consolidating concrete

vibration of self consolidating concrete-75

In the submerged zone, magnesium and hydrogen carbonate ions precipitate a layer of brucite, about 30 micrometers thick, on which a slower deposition of calcium carbonate as aragonite occurs.

These layers somewhat protect the concrete from other processes, which include attack by magnesium, chloride and sulfate ions and carbonatation.

The resulting expansion may cause destruction of the material.

Far less common are pop-outs caused by the presence of pyrite, an iron sulfide that generates expansion by forming iron oxide and ettringite. hydration of clay minerals in some aggregates, may lead to destructive expansion as well.

Sulfates in solution in contact with concrete can cause chemical changes to the cement, which can cause significant microstructural effects leading to the weakening of the cement binder (chemical sulfate attack).