Darex Corrosion Inhibitor (DCI) was specified for use in the Dogfish Bay Bridge on SR 308 in Kitsap County. The bridge is a 90-foot long structure located within a tidal zone. The superstructure is an 18-inch deep pre-stressed concrete slab. The end piers and two intermediate piers each consist of six, 16 1/2-inch pre-stressed concrete piles. DCI was added to all concrete used in the slab and piles except for four control piles (one in each pier). The supplier, Grace Construction Products, claims that the Calcium Nitrite contained in DCI will, when used as an additive in the recommended dosage, strengthen the passivating film around the reinforcing steel "making it more resistant to chloride penetration," thereby protecting the steel against corrosion. (The process is explained in detail in Appendix A.) However, only half of the recommended amount of DCI was added to the test sections. At this dosage, DCI appears to be no more effective than standard Portland Cement Concrete in preventing corrosion of the reinforcing steel.
August 24, 2007
Washington (State). Dept. of Transportation.
- # of Pages: 104 p., 927 KB (PDF)
- Subject: Bridge foundations, Bridges, Calcium nitrite, Concrete, Corrosion, Corrosion resistant materials, Deterioration, Portland cement.
- Keywords: Darex Corrosion Inhibitor, DCI, Calcium Nitrate, chloride, bridge substructure, Dogfish Bay Bridge, SR 308.
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This abstract was last modified April 29, 2008