CATHODIC PROTECTION OF STEEL REINFORCED CONCRETE STRUCTURES USING A GALVANIC ZINC HYDROGEL SYSTEM

摘要

There are over 500,000 condominium units along the Florida coastline, most of which havernexperienced significant corrosion of their steel reinforcements due primarily to chloride intrusion fromrnthe ocean salt spray. Some of the condominium associations in Florida have in the past five yearsrnrecognized that cathodic protection is the only rehabilitation method that will truly prevent the corrosionrnof the reinforcing steel and the resultant concrete spalling and delamination. The installations of arngalvanic zinc-hydrogel system will be described in detail, and monitoring data will be presented for atrnleast six months of active service.rnThe system consists of a 10-mil zinc foil bonded to an ionically conductive hydrogel adhesive,rnwhich is applied directly to the surface of the steel-reinforced concrete. A copper wire connects the zincrnanode to multiple steel rebars. The performance is monitored by measuring the current flow in the wire,rnby measuring the amount of zinc consumed or, more generally, by taking depolarization readings atrnregular intervals. All of these measurements are an indication of the performance of the galvanic systemrnand the corrosion of the steel rebars that is being prevented.