ABSTRACT
The electromagnetic interference (EMI) shielding offered by cement pastes with conductive addition (CNFs) has been evaluated in the frequency range between 0.5 and 1.0 GHz. On the contrary, there are many studies on polymeric conductive composites with discontinuous conductive carbon fibers, CNFs, and carbon nanotubes. In addition to reflection and absorption, another mechanism is multiple reflections. This refers to the reflection that is produced in several surfaces of inner faces inside the material. The parameters selected to evaluate the EMI shielding of the cement pastes were the reflection and the total shielding, which included reflection and absorption. Specimens consisted of cylindrical samples with 100 mm diameter and 10 mm thickness. Independent of the type of mechanism, loss by EMI shielding is typically expressed in decibels. In general, the power of the transmitted wave will be the difference between the incident power and the sum of the reflected power and absorbed power.
