Measurement of accelerated steel corrosion in concrete using Ground-penetrating radar and a modified half-cell potential method

Wai Lok Lai, Thomas Kind, Markus Stoppel, Herbert Wiggenhauser

Research output: Journal article publicationJournal articleAcademic researchpeer-review

31 Citations (Scopus)

Abstract

A new approach is presented to evaluate corrosion of steel bars in concrete by 1.5- and 2.6-GHz ground-penetrating radar (GPR) and a modified half-cell potential method. Changes in time-lapsed travel times, amplitudes, and peak frequencies that are associated with short-time Fourier transform spectrograms of the bar reflections were continuously measured. The year-long corrosion process of the reinforcement bar rapidly accelerated within a few days by impressing direct current across a pair of embedded reinforcement bars, which served as the anode and cathode. When corrosion started, the travel times, amplitudes, and frequency spectra of the bar reflection changed. The results were analyzed by dividing the material's response into three phases (NaCl contamination, depassivation, and corrosion). The writers attribute the phenomena of the first two phases to the ionic conduction and interfacial polarization effect, described in the lowfrequency regime of complex dielectric permittivity outlined in the Maxwell-Wagner effect. The remaining phase corresponds with the appearance of large and multiple interfaces among steel, concrete, corrosion product, and cracks, in addition to the upward movement of the corrosion product to the concrete surface that intercepts wider radar footprints. The findings, based on time lapse measurements, provide a basis to further apply the GPR technique to spatial measurements in laboratory and field studies.
Original languageEnglish
Pages (from-to)205-220
Number of pages16
JournalJournal of Infrastructure Systems
Volume19
Issue number2
DOIs
Publication statusPublished - 14 Aug 2013
Externally publishedYes

Keywords

  • Accelerated steel corrosion in concrete
  • Ground-penetrating radar
  • Half-cell potential
  • Short-time fourier transform

ASJC Scopus subject areas

  • Civil and Structural Engineering

Cite this