Patent ID: 6322691
Filing Date: 2001-11-27
Classification: C04B,C23F,C25F,E02D,E04C

Abstract:
A process for electrochemical treatment of a predetermined portion of a contaminated concrete structure having an exposed surface area and embedded steel reinforcement, wherein an electroconductive material is applied to said exposed surface area of the concrete to form a distributed electrode, a source of DC voltage is applied to said electroconductive material, as a positive terminal, and to said embedded steel reinforcement, as a negative terminal, and wherein said DC voltage is applied to impart a distributed current flow, of predetermined current density in relation to surface area of the steel reinforcement, between said applied electroconductive material and said embedded steel reinforcement, and wherein said DC voltage and said distributed current flow are continued until a predetermined current flow of at least about 500 ampere-hours of current per square meter of surface area of said embedded steel reinforcement has flowed between said terminals, and wherein said treatment is terminated as a function of said predetermined current flow in relation to the surface area of said embedded steel reinforcement, the improvement characterized by(a) said electroconductive material being applied to only a predetermined fractional portion of the exposed surface area of said predetermined portion to be treated,(b) said predetermined fractional portion being less than the entire exposed surface area of said predetermined portion to be treated,(c) said distributed current flow being applied to said predetermined fractional portion at a current density which is in a ratio to said predetermined current density which is inversely proportional to the ratio of said predetermined fractional portion to the entire exposed surface area of said predetermined portion to be treated,(d) said treatment being continued until said predetermined current flow has been reached with respect to the surface area of embedded steel reinforcement for the entire said predetermined portion to be treated, and(e) said treatment being thereupon terminated as to the entire said predetermined portion to be treated.