Optimization of electromagnetic wave absorption bandwidth of cement-based composites with doped expanded perlite

The use of expanded perlite as an EMW transmitting aggregate (ETA) is proposed to optimize the impedance matching of cement-based composite. The introduction of ETA significantly optimizes the impedance matching between the specimens and free space, increases the transmission distance and absorption probability of EMW, as well as causes the scattering of EMW. ETA and EMW absorbing aggregate (EAA) are used in combination to afford broad band and high absorption. The maximum absorption bandwidth with reflectivity of <−10 dB is approximately 14 GHz in the 2–18 GHz range. The optimal contents of EAA and ETA are 30–40% and 7–13%, respectively.