Humidity dependence of apparent dielectric constant for DSP cement materials at high frequencies

Abstract

The relationship between humidity and dielectric constant for cement densified with small particles (DSP) has been studied in the relative humidity range 0%-93% and the frequency range 1 MHz to 1 GHz. The calculated dielectric constant appears to increase with increasing humidity as a linear relation at fixed frequency. According to experimental data and basic principles for dielectrics, two experimental expressions are suggested for heterogeneous dielectric materials to describe the observed behavior of the dielectric constant. The expressions fit the experimental data well in the frequency range studied. Apparent dielectric constant decreases with increasing frequency. Polarization of DSP cement is also discussed.