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SPRAYED ZINC GALVANIC ANODES FOR CONCRETE MARINE BRIDGE SUBSTRUCTURES.
| 题名： | SPRAYED ZINC GALVANIC ANODES FOR CONCRETE MARINE BRIDGE SUBSTRUCTURES. |
| 作者： | Sagues-AA; Powers-RG |
| 关键词： | CATHODIC-PROTECTION; CORROSION-; GALVANIC-ANODE; SPRAYED-ZINC; CONCRETE-BRIDGES; REINFORCING-STEELS; FIELD-TESTS; LABORATORY-TESTS; METHODOLOGIES-; STRATEGIC-HIGHWAY-RESEARCH-PROGRAM |
| 摘要： | A low-cost method for galvanic cathodic protection of reinforcing steel in concrete was examined. In this method, arc-sprayed zinc is deposited on the external concrete surface of steel-reinforced marine substructure bridge components, which are normally subject to corrosion of the reinforcement as a result of chloride ion contamination of the concrete. The concrete cover of corrosion-damaged substructure components is removed, exposing the reinforcing steel. After sandblasting, the zinc is arc-sprayed over the exposed steel and surrounding concrete, creating a 1/2 mm thick galvanic anode, which is in electronic contact with the steel and in electrolytic contact with the water in the concrete pores. In this investigation, the ability of the system to deliver protective current was examined by experiments in the laboratory and at field installations at bridges in the Florida Keys. The field tests showed that the anodes retained physical integrity over at least 4 1/2 years in a subtropical environment. The laboratory tests revealed that in the marine substructure conditions of interest, concrete resistivity does not represent a main limiting factor in the performance of the galvanic anodes. However, absence of direct wetting of the anode surface can result in long-term loss of adequate current delivery, even when the concrete is in contact with air of 85 percent relative humidity. The results indicate that periodic water contact is necessary for long-term anode performance. The method can be viewed as a competitive alternative to impressed-current cathodic protection systems, and also as a considerable improvement over simple gunite repair of corrosion-damaged substructure concrete. |
| 总页数： | 1994. pp85 (46 Fig., 10 Tab., 34 Ref.) |
| 报告类型： | 科技报告 |
相关文献
- Evaluation of Anodes for Galvanic Cathodic Prevention of Steel Corrosion in Prestressed Concrete Piles in Marine Environments in Virginia; Final rept. 1996.10-Jun 99
- EVALUATION OF ANODES FOR GALVANIC CATHODIC PREVENTION OF STEEL CORROSION IN PRESTRESSED CONCRETE PILES IN MARINE ENVIRONMENTS IN VIRGINIA
- GALVANIC CATHODIC PROTECTION OF REINFORCED CONCRETE BRIDGE MEMBERS USING SACPJnCIAL ANODES ATTACHED BY CONDUCTIVE ADHESIVES
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