U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
|This report is an archived publication and may contain dated technical, contact, and link information|
Publication Number: FHWA-RD-02-107
Future research will begin to focus on two regions, (1) the anolyte/concrete interface and (2) the concrete/steel interface. In addition, the effects of sandblasting and various electrolytes on current efficiency will be investigated. Testing will include previously used nondestructive techniques as well as the destructive evaluation of samples. The rational for destructive evaluation is to ascertain a clearer understanding of changes within the concrete and at the concrete/steel interface. Currently, pH, XRD, and XPS measurements, as well as visual inspection are being planned for the interior portions of the concrete.
The upcoming testing will be performed on existing specimens as well as on new specimens with a different design. It is anticipated that by combining favorable features from prior specimens, this improved specimen design will provide additional insight into the changes occurring within the concrete during ECE. These specimens will contain the monitoring devices used in the Type I specimens, but the cathode area will be increased. This will be achieved by not only increasing the amount of steel in a single layer, but the number of layers will also be increased. In addition, some of the samples will include embedded pH electrodes to evaluate changes in alkalinity during ECE. An illustration of the proposed Type III specimen is shown in figure 27. Furthermore, to provide a baseline for this study, some of the new specimens will not contain chlorides.
Modeling the expected beneficial life of a treated structure will begin during the upcoming research period. This will be done using specimens that were treated during the extraction portion of this study. In addition, the possibility of evaluating previously treated structures is being explored.
Topics: research, infrastructure, structures
Keywords: research, structures, Cathodic protection, chloride ions, electrochemical chloride extraction, rehabilitation of concrete bridges, reinforced concrete, removal of chloride, steel corrosion in concrete
TRT Terms: research, infrastructure, Facilities, Structures, Bridges, Concrete--Foundations and piers, Reinforced concrete--Electrochemical chloride extraction, Reinforced concrete--Corrosion, Cathodic protection, Chlorides, Electrochemical processes, Reinforced concrete bridges