Title: Differential Effective Medium Theory for the Chloride Diffusivity of Concrete

Author(s): Jian-jun Zheng, Xin-zhu Zhou, Hong-yan Xing, and Xian-yu Jin

Publication: Materials Journal

Volume: 112

Issue: 1

Appears on pages(s): 3-10

Keywords: chloride diffusivity; differential effective medium theory; spheriodal aggregate particle

DOI: 10.14359/51687233

Date: 1/1/2015

Abstract:
The purpose of this paper is to present a differential effective medium scheme for the chloride diffusivity of concrete with spheroidal aggregate particles. By taking the interfacial transition zone (ITZ)-coated aggregate particle as an “equivalent aggregate particle,” the three-phase concrete is reduced to a two-phase composite material. The differential effective medium theory is then adopted to derive an analytical approximation for the chloride diffusivity of concrete. After the validity of the analytical approximation is verified with two sets of experimental results, the effects of various key factors on the chloride diffusivity of concrete are evaluated quantitatively. Numerical results indicate that the chloride diffusivity of concrete increases with an increase in chloride diffusivity and thickness of ITZ, but decreases by increasing the aggregate aspect ratio and maximum aggregate diameter. It is also found that the aggregate gradation has a significant influence on the chloride diffusivity of concrete.