Correlating the Chloride Diffusion Coefficient and Pore Structure of Cement-Based Materials using Modified Noncontact Electrical Resistivity Measurement

Abstract

The electrical resistivity of hardened cement-based materials was measured in this work by a modified noncontact electrical resistivity measurement (MN-CM). The resistivity was further processed to compute the chloride diffusion coefficient (Dρ) using the Nernst-Einstein equation. Also, the rapid chloride migration test (RCM) was carried out to obtain the chloride migration coefficient (DRCM), and the relationship between Dρ and DRCM has been established. The obtained Dρ was further correlated to the pore structure parameters characterized by low-field nuclear magnetic resonance (NMR) spectroscopy. The results show that the DRCM is more sensitive to the change of pore connectivity, while Dρ is more sensitive to the change of porosity. The Dρ is smaller than DRCM since it strictly follows the Nernst-Einstein equation while RCM neglects the other driving forces such as capillary sorption and concentration gradient. It is concluded that the proposed MN-CM can obtain the chloride diffusion coefficient of saturated cement-based materials in a quick, stable, and reliable manner.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

The financial support from the Ministry of Science and Technology of the People's Republic of China (973 Program) (Grant No. 2015CB655103) and the National Natural Science Foundation of China (Grant Nos. 51578497 and 51678529) is gratefully acknowledged.

Keywords and Phrases

Chloride diffusion coefficient; Electrical resistivity; Formation factor; Low-field nuclear magnetic resonance (NMR); Pore structure

International Standard Serial Number (ISSN)

0899-1561; 1943-5533

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 American Society of Civil Engineers (ASCE), All rights reserved.

Publication Date

01 Mar 2019

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