Thaumasite Form of Sulfate Attack
-A Review of the Deterioration Mechanism and the Evaluating Method of Risk-
By N. Yoshida and K. Yamada
Concrete Journal, Vol.43, No.6, Jun. 2005
- Synopsis
- In Western countries, new chemical deterioration mechanism of the concrete, "Thaumasite form of Sulfate Attack" draws attension. Thaumasite is formed when the sulfate ion mainly from the soil and carbonate ion mainly from the carbonate aggregate react with the calcium silicate hydrate under the condition of low temperature and existence of water. Thaumasite softens the cement composition and cause cracking and spalling of the concrete surface. Authors have obtained the knowledge about this deterioration from the reports by Western researchers, and would like to supply useful information in this paper.
- Keywords:
- thaumasite, sulfate attack, sulfate ion, carbonate ion, carbonate aggregate, conditon of low temperature, oxidation of pyrite
