Process for rehabilitating internally reinforced concrete by removal of chlorides
US5198082A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1989 |
| Grant date | Mar 30, 1993 |
| Priority date | — |
| Expiry date | Jun 9, 2009 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE04G23/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for rehabilitation of internally reinforced concrete which comprises the temporary application of an adherent coating of an electrolytic material to surface areas of the concrete. Distributed electrode means, preferably a wire grid, is embedded in the adherent coating. Voltage sufficient to develop a current of about 1-5 amps/m.sup.2 is applied between the reinforcement and the distributed electrode, to cause migration of chloride ions from the concrete into the electrolytic coating. When the chloride content of the concrete has been reduced to a desired level, the voltage is discontinued and the electrolytic coating and distributed electrode are removed. A highly preferred material for the adherent electrolytic layer is cellulosic pulp, premixed with water or other solution (such as calcium hydroxide) in a nozzle and sprayed onto the surface of the area being treated. Desirably, the distributed electrode is formed of a ferrous material reactive with chlorine, to minimize the release of free chlorine gas into the ambient. Particularly for tensioned reinforcement, the process monitors polarization of the tensioned steel to prevent hydrogen embrittlement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.