An ultra-wideband electromagnetic shielding concrete based on multi-scale conductive fillers

In order to address the challenge of balancing strength and high shielding performance in concrete, an ultra-wideband electromagnetic shielding concrete was developed in this work by incorporating nano-scale carbon black, micro-scale graphite, and millimeter-scale steel fibers to construct a multi-scale hierarchical conductive network. The results demonstrate that the shielding concrete exhibits excellent mechanical and shielding properties. The electrical conductivity of the shielding concrete reaches up to 0.17 S/m. In the MHz frequency range, the average SE exceeds 30 dB, while in the GHz range, the SE is significantly higher, ranging between 65–109 dB. Meanwhile, the 28-day compressive strength of the shielding concrete remains above 45 MPa, complying with the Chinese National Standard GB50010.