Measurement of the complex refractive index of concrete at 57.5 GHz
- 1 January 1996
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Antennas and Propagation
- Vol. 44 (1) , 35-40
- https://doi.org/10.1109/8.477526
Abstract
The complex refractive index of concrete is measured at 57.5 GHz by the combined use of free-space reflection and transmission methods. The measured refractive index of the concrete 14 months after concreting was 2.55-j0.084. This index, in particular the imaginary part, is sensitive to the curing time after concreting and the water content. The transmission coefficient of a concrete plate, mainly determined from the imaginary part of the complex refractive index, is less than -20 dB/cm when the concrete is fresh and moist and reaches -9 dB/cm after aging for fourteen months. In contrast, the reflection coefficient of a concrete plate is less dependent on water content.Keywords
This publication has 3 references indexed in Scilit:
- Calibration techniques for free space reflection coefficient measurementsIEE Proceedings A Science, Measurement and Technology, 1992
- AVNA-based polarimetric scatterometersIEEE Antennas and Propagation Magazine, 1990
- Recent Advances in Broad-Band VHF and UHF Transmission Line Methods for Moisture Content and Dielectric Constant MeasurementIEEE Transactions on Instrumentation and Measurement, 1979