Interpretation of impedance spectroscopy of cement paste via computer modelling - Part I Bulk conductivity and offset resistance

R. T. Coverdale*, B. J. Christensen, H. M. Jennings, T. O. Mason, D. P. Bentz, E. J. Garboczi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

60 Scopus citations

Abstract

Computer simulation of impedance spectroscopy (IS) of hydrating cement paste, using a three-dimensional, four-phase model, is described. Two puzzling features of experimental IS results, the possible offset resistance in the Nyquist plot and the sharp decrease in normalized conductivity within the first 50 h of reaction, have been studied using the computer simulation model. Insight is provided into these features using the ability of the model to compare quantitatively microstructure and properties. It is concluded that the offset resistance is an experimental artefact, and does not directly relate to microstructure. The drop in conductivity during the first 50 h is shown to be a consequence of a gradual shift from parallel-dominated to series-dominated behaviour of the electrical conductivity, as microstructural modifications take place during hydration, causing the capillary pore structure to become more tortuous. This tortuousity can also explain the high-frequency impedance behaviour in terms of a two-arc response.

Original languageEnglish (US)
Pages (from-to)712-719
Number of pages8
JournalJournal of Materials Science
Volume30
Issue number3
DOIs
StatePublished - Jan 1 1995

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Interpretation of impedance spectroscopy of cement paste via computer modelling - Part I Bulk conductivity and offset resistance'. Together they form a unique fingerprint.

Cite this