In this paper, dielectric measurements were carried out to obtain conductivity, permittivity (real and imaginary parts) and loss tangent of Dead Sea water. These dielectric properties were measured using two different...In this paper, dielectric measurements were carried out to obtain conductivity, permittivity (real and imaginary parts) and loss tangent of Dead Sea water. These dielectric properties were measured using two different methods: Vector Network Analyzer “VNA” (Dielectric Assessment Kit “DAK”) and Four Probe method, all measurements taken at room temperature (25<span style="font-size:12px;white-space:nowrap;">˚</span>C). The collected data has been analyzed in the frequency range (200 MHz - 9 GHz), by making a comparison between the measured data for Dead Sea water and distilled water, the results have shown that a huge difference in dielectric properties for the two samples. The conductivity of Dead Sea water is much larger than the conductivity of distilled water, which has been expected because of the fact of the high salinity of Dead Sea water.展开更多
The motivation for this study was to investigate the representative volume element （RVE） needed to correlate the nondestructive electromagnetic （EM） measurements with the con- ventional destructive asphalt pavemen...The motivation for this study was to investigate the representative volume element （RVE） needed to correlate the nondestructive electromagnetic （EM） measurements with the con- ventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar （GPR） measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer （VNA） and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore vol- ume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.展开更多
文摘In this paper, dielectric measurements were carried out to obtain conductivity, permittivity (real and imaginary parts) and loss tangent of Dead Sea water. These dielectric properties were measured using two different methods: Vector Network Analyzer “VNA” (Dielectric Assessment Kit “DAK”) and Four Probe method, all measurements taken at room temperature (25<span style="font-size:12px;white-space:nowrap;">˚</span>C). The collected data has been analyzed in the frequency range (200 MHz - 9 GHz), by making a comparison between the measured data for Dead Sea water and distilled water, the results have shown that a huge difference in dielectric properties for the two samples. The conductivity of Dead Sea water is much larger than the conductivity of distilled water, which has been expected because of the fact of the high salinity of Dead Sea water.
基金funded by the Finnish Transport Administration (FTA)
文摘The motivation for this study was to investigate the representative volume element （RVE） needed to correlate the nondestructive electromagnetic （EM） measurements with the con- ventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar （GPR） measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer （VNA） and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore vol- ume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.
