A contactless measurement setup measures the magnitude and phase of reflection coefficients of metal-backed asphaltic concrete specimens in the frequency range of 12.4-18.0 GHz. A vector network analyzer, spot-focusing horn lens antenna, mode transitions, and coaxial cables measure free-space complex reflection coefficients. The complex permittivity is calculated from the measured reflection coefficient of metal-backed asphaltic concrete specimens, by an iterative procedure that minimizes an error function. A significant difference exists between the dielectric properties of the dry and wet specimens. Therefore, the presence of moisture can be detected. The moisture content of wet specimens is deduced from the complex permittivities of dry and wet specimens using the effective medium approximation for asphaltic concrete mixtures. The results include the moisutre content and dielectric properties of asphaltic concrete specimens at different air void contents.
|Original language||English (US)|
|Number of pages||8|
|Journal||IEEE Transactions on Geoscience and Remote Sensing|
|State||Published - Sep 1991|
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Earth and Planetary Sciences(all)