Research on the electromagnetic wave absorption properties of GNPs/EMD cement composite

•The dispersion of GNPs in cement was characterized sufficiently.•The effect of GNPs and EMD on permittivity and permeability of cement composites were fully discussed.•The mechanism of GNPs and EMD on EMW absorption properties were analyzed. Electromagnetic wave pollution has been paid more and more attention with the improvement of human ecological awareness. Hence urban construction materials with electromagnetic wave absorption properties will be demanded widely in the future. In this paper, the electromagnetic wave absorption properties of cement composites with various dosage graphene nanoplates (GNPs) and electrolytic MnO2 (EMD) are investigated and the electromagnetic reflectivity loss, electromagnetic parameter of cement composites are tested and discussed in frequency range of 2–18 GHz. The effect of GNPs and EMD on complex permittivity, complex permeability of cement composites is analyzed, and further mechanism analysis are discussed combined with XRD and SEM micrographs. Experimental results show that cement composites with 1.0% GNPs and 10.0% EMD exhibit lower electromagnetic reflectivity loss curves, which is the optimal dosages. Lowest electromagnetic reflectivity loss curve is achieved when 1.0% GNPs and 10.0% EMD incorporated together and the effective absorption frequency width (lower than −10 dB) is 5.8 GHz, of which more than 90% EMWs energy is translated to thermal energy and absorbed by matrix, reaching similar EWMs absorption effect of absorption coating materials. Besides, the imaginary part of complex permittivity and dielectric loss tangent of cement composites increases when GNPs and EMD added, indicating better EMWs absorption performance.