THE SULFURIC ACID RESISTANCE OF CONCRETE WITH BLAST FURNACE SLAG

The deterioration of concrete by sulfuric acid attack in sewage environments has become a serious problem. In this study, it was shown that the resistance to sulfuric acid of mortar and concrete can be improved by using a blast-furnace slag fine aggregate to the total amount of fine aggregate. When mortar or concrete reacts to sulfuric acid, dihydrated gypsum film is formed around the particulate of the fine aggregate. This dihydrated gypsum film could retard the penetration of sulfuric acid, thus improving the resistance to sulfuric acid. However, the resistance to sulfuric acid depends on the hardness of the dihydrated gypsum film.