Effect of Mineral Admixtures on Durability of Concrete Structure Subjected to Alkaline Saline Corrosions

Effect of a combination of alkali ions, sulfate ion and chloride ion on durability of concrete structures was analyzed, and the effect of different mineral admixtures on deterioration caused by Cl- penetration, sulfate attack and alkali-silica reaction was investigated. It is shown from wetting-drying test that sulfate attack on concrete was greatly relieved in high Cl- concentration solution, but diffusion test showed that Cl- diffusion was accelerated by SO4 2- ion existence as SO4 2- may incorporate with aluminum phase prior to Cl- ion. Replacement of cement with mineral admixtures such as ground blast furnace slag (SL) and metalaolin (MK) were beneficial for absorption of Cl- ion penetrated into paste, while ASTM C441 showed that fly ash (FA), metakaolin and natural zeolite (NZ) exhibited effectiveness in controlling Alkali-silica reaction (ASR).