TY - JOUR
T1 - Assignment of features in impedance spectra of the cement-paste/steel system
AU - Ford, S. J.
AU - Shane, J. D.
AU - Mason, T. O.
N1 - Funding Information:
This work was supported by the NSF Science and Technology Center for Advanced Cement-Based Materials under grant no. CHE-91-20002.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1998
Y1 - 1998
N2 - This paper presents a systematic study of the features seen in typical Nyquist plots (-imaginary vs. real impedance) for cement-paste/steel systems and discusses the assignment of each feature to its appropriate origin, e.g., bulk, contact, interface, product layer, etc. Assignments are made based upon as many considerations as possible - dc measurements, sample geometry, capacitance, local chemical modifications, alternative electroding schemes, etc. In addition to three distinct arcs from lowest (mHz) frequency to highest (MHz) frequency (dueto product layer, interfacial reaction, and bulk, respectively), a fourth arc is sometimes observed between the bulk and interface arcs. When this occurs in paste-only systems, this arc is attributable to imperfect electrodes due to drying/shrinkage. In composite systems, e.g., cement with conductive chopped fibers added, this arc is clearly a "bulk" feature and an important indicator of microstructural inhomogeniety.
AB - This paper presents a systematic study of the features seen in typical Nyquist plots (-imaginary vs. real impedance) for cement-paste/steel systems and discusses the assignment of each feature to its appropriate origin, e.g., bulk, contact, interface, product layer, etc. Assignments are made based upon as many considerations as possible - dc measurements, sample geometry, capacitance, local chemical modifications, alternative electroding schemes, etc. In addition to three distinct arcs from lowest (mHz) frequency to highest (MHz) frequency (dueto product layer, interfacial reaction, and bulk, respectively), a fourth arc is sometimes observed between the bulk and interface arcs. When this occurs in paste-only systems, this arc is attributable to imperfect electrodes due to drying/shrinkage. In composite systems, e.g., cement with conductive chopped fibers added, this arc is clearly a "bulk" feature and an important indicator of microstructural inhomogeniety.
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U2 - 10.1016/S0008-8846(98)00156-2
DO - 10.1016/S0008-8846(98)00156-2
M3 - Article
AN - SCOPUS:0032297991
SN - 0008-8846
VL - 28
SP - 1737
EP - 1751
JO - Cement and Concrete Research
JF - Cement and Concrete Research
IS - 12
ER -