Enhancing the electromagnetic shielding and impact resistance of a reinforced concrete wall for protective structures

Abstract

Electromagnetic interference shielding has attracted attention in design processes for reducing radiation to protect humans or equipment. Traditional shielding constitutes adding strengthening, conductive paints, conductive fibers, or grids to non-damaged structures. Few studies have considered using hybrid reinforcement methods for shielding effectiveness or examined the relationship between damaged areas and shielding effectiveness. We prepared a reinforced concrete (RC) wall with different steel fiber contents, metallic grid/mesh reinforcement, and hybrid reinforcement and created damage areas via impact load. Compared with 300 mm thick RC and single-type reinforced specimens, the hybrid reinforced specimens had an approximately 25.9 times and 2.4 times higher shielding effectiveness, respectively. Specimens reinforced with metallic mesh exhibited less than 150% of free space area ratio and more than 30 dB shielding effectiveness. The hybrid metallic mesh and facultative metallic grid achieved over 40 dB. Hybrid reinforced specimens exhibited improved impact resistance and great shielding effectiveness in damaged conditions.