Modeling university of cape town chloride conduction test for concrete

Among variety of experimental techniques dealing with durability of concrete, the University of Cape Town based Chloride Conduction Test exudes a benchmark in its setup and resolve to index diffusion coefficient of chloride in concrete. This paper aims to simulate the electrochemical basis of the Chloride Conductivity Test with regard to assessing its underlying assumptions. Proposition of the governing equations is presented for evaluating the effect that changes occurring during the test could have in terms of deviations from steady state conditions upon which conductivity offered by the test are based. Advantage is taken of COMSOL Multiphysics to solve the Nernst-Planck equations used to describe the conductivity and migration behavior of the test problem. The formulation of the coupled electro-migration equation is used to investigate potential changes in the diffusibility ratio, or inverse formation factor, which may occur during the test. Results are presented to underscore the effects that migration away from pretreatment chloride level could have on the diffusibility ratio by means of chloride changes and conductivities data mined from the literature.