Nano-SiC Modified Iron Tailings Foam Concrete: Synergistic Modulation of Pore Structure, Mechanical and Dual-Band Wave Absorption Properties
摘要
In order to alleviate the problems of bulk solid waste disposal of iron tailings and electromagnetic wave pollution, a composite iron tailings/silicon carbide nanocomposite foam concrete wave-absorbing material was designed in this study. By replacing the cement matrix with iron tailings (20 wt.%) and using nano-silicon carbide doping to achieve functional modification, the mechanism of iron tailings-nano-silicon carbide synergistic effect on foam concrete mechanical and electrical conductivity was systematically revealed. The experimental results show that when the content of iron tailings reaches 20 wt.%, the average pore size increases from 235 μm to 277 μm, and the improvement of pore connectivity promotes the formation of a conductive network. When the content of nano-silicon carbide is 8 wt.%, the compressive and flexural strength reached a maximum of 2.51 MPa and 1.28 MPa, respectively, which increased 25.5% and 37.63%, respectively, compared with the control group. The composite material exhibits a bimodal absorption characteristic in the X-band and Ku-band, producing reflection loss peaks of -24.50 dB and -19.50 dB at 12.38 GHz and 14.00 GHz, in particular. The valid absorbing bandwidths are 1.67 GHz (10.73–12.4 GHz) and 1.4 GHz (13.31–14.71 GHz).