Electromagnetic Wave Absorption Properties of Cement Filled with Carbon Black

Using the dielectric loss property of carbon black , cement-based composites were prepared by introducing carbon black into cement. The reflection losses were studied using arched testing method in the frequency range of 2~18 GHz. The results showed that the absorption properties were improved in high frequency. The filling ratio of carbon black as well as the thickness of samples had influence on the absorption properties. The lowest reflection loss of-10.6 dB was obtained at 18 GHz of 5wt.% carbon black filled cement with thickness of 20mm. The new material can be used for building indoor electromagnetic radiation protection.