A Laboratory Approach to Determine RCC Mixture Electrical Characteristics Based TDR Data

This work deals with using Time Domain Reflectometry (TDR) to measure the electrical properties of the Roller Compacted Concrete (RCC). It is well known that TDR provides a nondestructive method to measure the dielectric constant towards an estimation of moisture content for soil materials. However, few studies used TDR to determine the moisture content in concrete because of the inability to obtain TDR traces after concrete hardens. To obtain TDR traces, a transmission circuit is initiated where a wave signal moves through the medium and reflects back in accordance with transmission line theory. In the literature, TDR waveform has been interpreted empirically to estimate the relative permittivity (or dielectric constant) and electrical conductivity in a given material relative to the determination of an associated water content. However, empirical models tend to ignore certain aspects related to the electrical properties of a medium which made interpretation of TDR measurements prone to systematic errors. In this paper, a new approach of test configuration and TDR response interpretation has been developed. For the test setup, the approach uses disposable metal probes that can be embedded into the concrete at different depths to obtain the TDR traces. The approach also employs the transmission line equation to estimate the dielectric constant, electrical conductivity, and reflectivity of an instrumented RCC mixture. This new approach yields estimates of the electrical properties of an RCC mixture and of their effect on the dielectric constant.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: 19p

Subject/Index Terms

Filing Info

  • Accession Number: 01763448
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-01524
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 10:59AM