Behavior of shrinkage-compensating concretes suitable for use in bridge decks, interim report phase 3

The object of this research was to determine if shrinkage-compensating concrete, when compared with Type l concrete, would reduce corrosion of the reinforcing steel in a bridge deck, hence minimizing deterioration. Specimens 1 ft (305 mm) by 6 ft (1830 mm) and 7 in. (180 mm) deep were first cracked and then subjected to freezing and thawing in the presence of deicing salts. After freeze-thaw cycling, tests were conducted to determine the porosity and chloride content of the respective concrete types. The results show clearly that the shrinkage-compensating concrete simulated bridge decks crack significantly less than the Type l concrete bridge decks. However, at locations where cracks are present, the development of corrosion will be the same for both types of concrete. The shrinkage-compensating concrete was found to have a slightly higher porosity than the Type l concrete. The chloride concentrati on determined after the freeze-thaw tests was higher for the shrinkage-compensating concrete at a 1-in. (25-mm) depth but at a depth of 2 in. (50 mm) the concentrations were the same for both concretes.Illinois Cooperative Highway & Transportation Research Program Ichtrp 162; Illinois Dept of Transportation 76/07; Transportation Department Federal Highway Administration 76/0