Title: Rapid Determination of the Chloride Diffusivity in Concrete by Applying an Electric Field

Author(s): Tang Luping and Lars-Olof Nilsson

Publication: Materials Journal

Volume: 89

Issue: 1

Appears on pages(s): 49-53

Keywords: cement pastes; chlorides; concretes; diffusion; electrical field; mathematical models; mortars (material); penetration tests; Materials Research

DOI: 10.14359/1244

Date: 1/1/1993

Abstract:
A mathematical model of ion diffusion under the action of a constant electric field was established, and the exact analytical solution of the differential equation in the model was found by considering semi-infinite diffusion. The relationship between the effective diffusion coefficient and the depth of chloride penetration under the action of an electric field was derived. A simple method for penetrating chlorides into concrete was proposed so that the chloride penetration profiles and depths could be obtained in a very short time. The chloride diffusivities in cement pastes and mortars with various water-cement ratios were determined by the method proposed in this paper as well as the conventional diffusion cells that took months to perform. The experimental results reveal a good correspondence with other researchers' findings and imply the possibility of evaluating chloride diffusivity in high performance concrete. They also predict chloride penetration into concrete structures in the field by short-time experiment.