Title: Relationships of Diffusivities and Age Factors between Analytical and Empirical Chloride Models for Decreasing Diffusivities

Author(s): Shengjun Zhou

Publication: Symposium Paper

Volume: 330

Issue:

Appears on pages(s): 55-66

Keywords: concrete, durability; service life; chloride diffusion; modelling; diffusivity; age factor.

DOI: 10.14359/51711240

Date: 9/26/2018

Abstract:
The relationships of diffusivities and age factors between the analytical and empirical models for chloride diffusion in concrete having a decreasing diffusivity are established. Apparent diffusivities and age factors in the empirical model are determined by fitting the chloride profiles obtained from the analytical model. The instantaneous diffusivities in analytical model are smaller than the corresponding apparent values. The ratios of two diffusivities decrease with time and age factor. Logarithm ratio of apparent diffusivity to the reference value at early age is proportional to the logarithm time ratio only after 2.5 years but not before while that of instantaneous diffusivity is so for all the time. The empirical model is suitable only when all inputs are determined based on the data after 2.5 years but not before. Furthermore, the ratio between hypothetical apparent diffusivity at reference time and the corresponding instantaneous value is obtained.