Research on cement-based fly ash for wave-absorbing properties

In order to research the wave-absorbing properties of fly ash in building materials, Type III fly ash was added in mortar at the thickness of 10~30 mm. After cured for 8months, wave-absorbing properties were researched with the arched testing method. The results show that fly ash has a maximum absorption 14.5 dB at 16.2 GHz. For mortar with 45% fly ash, the bandwidth for 6 dB is over 10 GHz, and in 10~18 GHz frequency range, all absorptions are more than 6 dB, and absorptions increase as frequency increases. Mortars with 15% fly ash at thickness of 15 mm and 25 mm have optimal absorption; bandwidth for 6 dB is over 9 GHz. A high potential application of fly ash in electromagnetic protection is expected.