Preparation and Electromagnetic-Wave-Absorption Properties of Cement-Based Materials with Graphite Tailings and Steel Fiber

The development of functional building materials that can absorb electromagnetic radiation is important for preventing and controlling electromagnetic pollution in urban areas. In this study, cement-based electromagnetic wave (EMW)-absorbing materials were created using graphite tailings (GTs) as a conductive admixture and steel fiber (SF) as an EMW absorber, which resulted in materials with a wide effective bandwidth and high reflection loss (RL). In particular, a GT–cement matrix with excellent mechanical and electrical properties was obtained. This study explored the influence mechanism of the SF content on the mechanical, electrical, and EMW-absorption properties of cement-based materials under the synergistic effect of GTs and SF. Findings demonstrate that the combination of GTs and SF notably improved the electrical and EMW-absorption characteristics of the cement-based materials. Optimal EMW-absorption properties were observed for a combination of 30% GTs and 6% SF. A developed cement-based EMW-absorbing material with a thickness of 20 mm displayed a minimum RL of −25.78 dB in the frequency range of 0.1–5 GHz, with an effective bandwidth of 0.953 GHz. Thus, the cement-based composite materials developed in this study have excellent EMW-absorption performance, which provides an effective strategy for preventing and controlling electromagnetic pollution in urban spaces.