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1. Report No. KTC-88-2 |
2. Government Accession No. | 3. Recipient’s Catalog No. | ||
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4. Title and Subtitle Calcium Nitrite as a Corrosion inhibitor in Reinforced Concrete Bridge Decks |
5. Report Date September 1988 S. Performing Organization Code KTC-88-2 |
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7. Author(s) T. Mopwood II, D.Q. Hunsucker and E.E. Courtney |
& Performing Organization Report No. KTC-90-2 |
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9. Performing Organization Name and Add ms# Kentucky Transportation Center Collego of Engineering University of Kentucky Lexington, KY 40506-0043 |
10.Work Unit No. (TRAIS) 11.Contract or Grant No. BRS 5129(4) BRM 7104(4) 13.Type of Report and Period Covered Final 14.Sponsoring Agency Code |
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12. Sponsoring Agency Nam* and Address Kentucky Transportation Cabinet Stats Office Building Frankfort, KY 40622 |
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15. Supplementary Notes Study Titles: Federal Aid Research Task No’s 17 & 19. "Use of Calcium Nitrite in Concrete for Bridge Decks.' Publication of this report was sponsored by the Kentucky Transportation Cabinet with the US Department of Transportation, Federal Highway Administration. |
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16. Abstract The use of calcium nitrite as a corrosion-inhibiting admixture in reinforced concrete has been studied on two bridges - the Kentucky 152 Bridge in Washington County and the Gose Road Bridge in Boyte County. Calcium nitrite was added to concrete used in the slabs, diaphrarns and barriers of the KY 152 bridge and only in the slab of the Good Road bridge. Construction of both structures was monitored in the fall of 1986. Placement of concrete on both bridges was satisfactory; however, problems were experienced in finishing the concrete. The finishing problems were related to: 1) concrete "stickiness*, 2) use of spinning-drum screed, 3) use of tyning for deck grooving and, 4) contractor inexperience with the concrete. The finishing problems included; 1) pulled or exposed aggregate, 2) pull cracks, 3) unclosed surface voids and 4) irregular grooves. Compressive strength of the calcium-nitrite admixed concrete for both bridges exceeded 8,000 psi at 28 days. Freeze-thaw tests of specimens from the Gose Road bridge concrete (that incorporated a super water reducer) indicated no deterioration at 360 freeze-thaw cycles, Half-cell, conrosion-potentiai tests were conducted on both bridge decks in March 1987. Those tests revealed no active corrosion in either bridge. In July 1987, conrosion-potentiai and polarization-resistance tests were performed using stainless-steel reference electrodes buried in concrete across the deck of the Gose Road bridge. Those tests revealed that reinforcing steel in the bridge was in a passive state and that no active corrosion was occurring. Recommendations are included on remedying concrete-finishing problems. It is recommended that other experimented bridges be constructed using calcium nitrite. |
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17. Key Words Bridge-decks reinforced concrete Calcium nitrite steel Chlorides Corrosion |
18. Distribution Statement Unlimited, with approval of the Kentucky Transportation Cabinet. |
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19. Security Class if. (of this report) Unclassified |
20. Security Class if. {of this page) Unclassified |
21. No. of Pages 28 | 22. Price | |
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1. Report No. KTC-88-2 |
2. Government Accession No. | 3. Recipient’s Catalog No. | ||
|
4. Title and Subtitle Calcium Nitrite as a Corrosion inhibitor in Reinforced Concrete Bridge Decks |
5. Report Date September 1988 S. Performing Organization Code KTC-88-2 |
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7. Author(s) T. Mopwood II, D.Q. Hunsucker and E.E. Courtney |
& Performing Organization Report No. KTC-90-2 |
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|
9. Performing Organization Name and Add ms# Kentucky Transportation Center Collego of Engineering University of Kentucky Lexington, KY 40506-0043 |
10.Work Unit No. (TRAIS) 11.Contract or Grant No. BRS 5129(4) BRM 7104(4) 13.Type of Report and Period Covered Final 14.Sponsoring Agency Code |
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12. Sponsoring Agency Nam* and Address Kentucky Transportation Cabinet Stats Office Building Frankfort, KY 40622 |
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15. Supplementary Notes Study Titles: Federal Aid Research Task No’s 17 & 19. "Use of Calcium Nitrite in Concrete for Bridge Decks.' Publication of this report was sponsored by the Kentucky Transportation Cabinet with the US Department of Transportation, Federal Highway Administration. |
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|
16. Abstract The use of calcium nitrite as a corrosion-inhibiting admixture in reinforced concrete has been studied on two bridges - the Kentucky 152 Bridge in Washington County and the Gose Road Bridge in Boyte County. Calcium nitrite was added to concrete used in the slabs, diaphrarns and barriers of the KY 152 bridge and only in the slab of the Good Road bridge. Construction of both structures was monitored in the fall of 1986. Placement of concrete on both bridges was satisfactory; however, problems were experienced in finishing the concrete. The finishing problems were related to: 1) concrete "stickiness*, 2) use of spinning-drum screed, 3) use of tyning for deck grooving and, 4) contractor inexperience with the concrete. The finishing problems included; 1) pulled or exposed aggregate, 2) pull cracks, 3) unclosed surface voids and 4) irregular grooves. Compressive strength of the calcium-nitrite admixed concrete for both bridges exceeded 8,000 psi at 28 days. Freeze-thaw tests of specimens from the Gose Road bridge concrete (that incorporated a super water reducer) indicated no deterioration at 360 freeze-thaw cycles, Half-cell, conrosion-potentiai tests were conducted on both bridge decks in March 1987. Those tests revealed no active corrosion in either bridge. In July 1987, conrosion-potentiai and polarization-resistance tests were performed using stainless-steel reference electrodes buried in concrete across the deck of the Gose Road bridge. Those tests revealed that reinforcing steel in the bridge was in a passive state and that no active corrosion was occurring. Recommendations are included on remedying concrete-finishing problems. It is recommended that other experimented bridges be constructed using calcium nitrite. |
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17. Key Words Bridge-decks reinforced concrete Calcium nitrite steel Chlorides Corrosion |
18. Distribution Statement Unlimited, with approval of the Kentucky Transportation Cabinet. |
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19. Security Class if. (of this report) Unclassified |
20. Security Class if. {of this page) Unclassified |
21. No. of Pages 28 | 22. Price | |
