Broadband Electrical Properties of Green Bricks

Frequency dependent complex permittivity of brick clay and green bricks was examined in a broad range of volumetric water content with a network analyzer measurement setup in the frequency range between 0.02 MHz - 5 GHz. Theoretical values of the materials permittivity were calculated with the well-known Lichtenecker-Rother model (ALRM) and compared to the measurements. A three phase model did not successfully explain the measured values. Effects of fluids and solid surfaces interaction as well as bound water effects should be included. For this additional process a critical volumetric water content level was found.