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Due to the complexity of the design of multilayer electromagnetic (EM) wave absorbing materials, it is difficult to establish the relationship between material parameters (type and filling ratios) and EM properties using traditional trial and error methods. Based on the measured EM parameters within a few materials and Boltzmann mixing theory, a database of EM parameters was thereafter built up. In this study, the genetic algorithm (GA) was used to design the multilayer wave-absorbing cement mortar. In order to verify this method, a multilayer mortar was fabricated and measured. The simulated and measured results are well consistent, which convincingly verifies computer-aided design. In addition, the optimized result expresses that the first layer as a matching layer guides EM waves into the interior of the material, while the other layers as absorption layers attenuate EM waves. The multilayer material may not meet the impedance gradient principle but still exhibits better EM wave absorption performance. The reflection loss (RL) of all optimized three layer sample is below –6.89 dB in the full frequency band and the minimum RL is –26.21 dB. This composite absorbing material and the GA method provide more design ideas for the design of future cement-based wave-absorbing materials and save a lot of time and material cost.

The development of practical and efficient electromagnetic wave (EMW) absorbing materials is a challenging research problem. A mussel-inspired molecular structure regulation strategy using polydopamine to increase the roughness and functional groups of the basalt fiber (BF) surface, thereby improving the interfacial adhesion. Herein, a novel BF-Fe3O4/CNTs heterostructure is synthesized through a dip-coating adsorption process. The three-dimensional network structure of Fe3O4/CNTs hybrid in-situ anchored on the surface of BF, which endows the composite to have good intrinsic magnetic and dielectric properties. Modulation of EMW absorption performance by controlling the addition of CNTs, the minimum RL of BF-Fe3O4/7C reaches to -40.57 dB at a thickness of 1.5 mm with CNTs addition of 7%. The enhanced EMW absorption performance of BF-Fe3O4/7C heterostructure may be attributed to the hollow magnetic Fe3O4 spheres and the synergistic effects of interfacial polarization, conduction loss, magnetic resonance loss and multiple reflection/scattering inside the BF. This work provides a simple pathway to design EMW absorbing materials with good environmental stability.