Analysis of Shielding Effectiveness of Reinforced Concrete Against High-Altitude Electromagnetic Pulse

This paper is focused on the analysis of the shielding properties of reinforced concrete under impinging high-altitude electromagnetic pulse. The reinforced concrete provides frequency-dependent shielding effectiveness mainly due to the embedded metallic grid rebars. For characterization of the concrete, three different configurations, i.e., concrete, rebar, and combined reinforced concrete, are analyzed in detail. In addition, the electromagnetic properties of concrete are quantitatively analyzed by its frequency dependence, moisture content, and material mixture ratio. According to the obtained results, as the rebar spacing decreases and the rebar diameter is increased, the transmission coefficient is gradually decreased. In particular, for reinforced concrete with built-in double layered rebar, it is possible to obtain a transmission coefficient approximately 40 dB less than that achieved by single rebar.