Concrete Deterioration by Deicing Salts: An Experimental Study

Concrete with dolomite coarse aggregate was obtained by coring existing Iowa highways. The concretes were of two types, those which were very durable under highway conditions and those which were low durability. Samples were experimentally deteriorated using wet/dry, freeze/thaw, and continuous soak conditions in solutions of magnesium chloride, calcium chloride, sodium chloride, magnesium acetate, magnesium nitrate, and distilled water in order to determine relative deterioration activities. Magnesium chloride was most destructive. Calcium chloride was next, and sodium chloride was relatively benign. Magnesium acetate produced severe crumbling and moderate fracturing, and magnesium nitrate caused moderately severe deterioration by crumbling and discoloration. Low durability concrete was somewhat more affected by distilled water freeze/thaw conditions than more durable material, but generally both types were severely damaged by magnesium and calcium salts. These results suggest that magnesium and calcium deicers may accelerate highway concrete deterioration