Abstract
The influence of gypsum on the behavior of chloride ion and corrosion of steel in mortar including ground granulated blast-furnace slag (BFS) were investigated. Gypsum was added to BFS. The decrease in the amount of bound chloride ion in mortar due to the addition of gypsum is thought to be related to the reduction of the amount of Friedel's salt. The chloride corrosion of steel by intrinsic chloride ion in mortar was accelerated by the addition of gypsum. The chloride corrosion of steel by intrinsic chloride ion was found to be related to the change in pore structure and the increase in soluble chloride content due to the addition of gypsum. The addition of gypsum had no effect on the chloride corrosion of steel by extraneous chloride ion in mortar.
