General Introduction to Part I

Abstract

Concrete structures are exposed to aggressive aqueous environments in very varied situations, and the range of aggressive species is wide. Among numerous examples, foundations and/or parts of structures in contact with groundwaters, soils or wastewaters may be subject to sulfate attack, and harbour and other maritime facilities are exposed to the action of seawater involving the combined action of magnesium, sulfates and chlorides. Dams, waterpipes and other structures exposed to the action of soft or carbonated waters suffer leaching and/or carbonation. Many agricultural and agrofood facilities (storage silos, animal houses etc.) suffer severe degradation notably linked with organic acids in waste water. The understanding of the mechanisms of degradation of cementitious matrices by these aggressive media is an essential step toward the development of concrete that performs well in these environments and toward the increase of the service life or the safety of the structures and facilities.