Title: Effect of Electrical Field on the Removal of Chloride Ions From Concrete Slabs

Author(s): L. Tang, L. Berntsson, J. Aavik, and L. O. Nilsson

Publication: Symposium Paper

Volume: 145

Issue:

Appears on pages(s): 597-608

Keywords: chloride ions; concretes; concrete slabs; cores; diffusion; electrical properties; Materials Research

DOI: 10.14359/4559

Date: 5/1/1994

Abstract:
In this study, 2 x 2 x 2-m reinforced concrete slabs with an overlay containing initial chloride contents of 0.2, 0.7, and 0.2 percent Cl were electrochemically treated. An electrical field at current densities of 0.7, 1.0, and 1.3 A/m 2 was applied across the overlay at biweekly intervals for a total duration of 8 weeks. During each intermission, the cores were taken from the slabs to determine chloride distribution profiles. Chloride diffusivities in concrete before and after electrochemical treatment were also determined by using a rapid method. The effects of an electrical field on chloride distribution profiles and chloride diffusivity in concrete are discussed. Results show that the electrochemical treatment has no apparent influence on chloride diffusivity, and that this treatment has a limit beyond which the further removal of chloride ions becomes difficult. It is difficult to remove chloride ions homogeneously from concrete using the reinforcement as a cathode.