A Study on Electromagnetic Wave Absorption by Cement-based Materials - Suppression of the Effects of Moisture -

A cement-based material, when used as an electromagnetic wave absorber, offers excellent weather resistance against rainwater and UV rays. However, since cement-based materials are porous, their moisture content is a concern because it can affect the electromagnetic wave absorption performance. In this study, we conducted experiments focusing on the water-cement ratio and the addition rates of polypropylene pellets (a dielectric material) and carbon powder (a resistive material) to suppress the effects of moisture content on electromagnetic wave absorption performance. The results showed that by setting the water-cement ratio at 30%, the polypropylene pellet content at 32%, and the carbon powder content at 6%, stable electromagnetic wave absorption can be achieved despite changes in moisture content.