Empirical Multiphase Dielectric Mixing Model for Cement-Based Materials Containing Alkali-Silica Reaction Gel


Alkali-silica reaction (ASR) is a common cause of concrete deterioration. Water (either in free or bound form), in the presence of reactive aggregates, plays a major role in the reaction itself and in the formation and expansion of the deleterious gel produced. Since microwave signals are sensitive to the presence of water in dielectric materials, microwave materials characterization techniques have the potential to detect and monitor ASR gel in concrete structures. Dielectric mixing models are physics-based models that relate the macroscopic (i.e., effective) dielectric constant of a material to the dielectric constant of its constituents and their respective volumetric contents. In this investigation, an empirical multiphase dielectric mixing model is developed in conjunction with measured dielectric constants of two sets of mortar samples with ASR-reactive and nonreactive aggregates at R-band (1.7-2.6 GHz). The proposed model is capable of closely predicting the effective (temporal) dielectric constant of the samples. The modeling results are validated by a comparison with the measured temporal dielectric constant of the samples, showing good agreement. Through this investigation, quantitative information on the influence of constituents of ASR-reactive mortar samples (including ASR gel) are obtained, and the pertinent results indicate significant potential for microwave materials characterization techniques for ASR detection and evaluation.


Electrical and Computer Engineering


National Science Foundation (U.S.)


This work was supported by the National Science Foundation, as a Collaborative Grant between Missouri University of Science and Technology and Georgia Institute of Technology, under Award 1234151.

Keywords and Phrases

Aggregates; Characterization; Concretes; Microwave Measurement; Mixing; Mortar; Permittivity; Produced Water; Silica; Alkali-Silica Reaction; Cement Based Material; Concrete Deterioration; Dielectric Mixing Model; Microwave Materials; Physics-Based Models; Quantitative Information; Reactive Aggregate; Dielectric Materials; Alkali-Silica Reaction (ASR) Gel; Cement-Based Materials; Dielectric Constant; Materials Characterization; Microwave Nondestructive Testing (NDT)

International Standard Serial Number (ISSN)

0018-9456; 1557-9662

Document Type

Article - Journal

Document Version


File Type





© 2017 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Sep 2017