Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4918336 | Construction and Building Materials | 2017 | 8 Pages |
Abstract
Utilization of silica fume and colloidal graphite in nickel fiber cement based composites as a mean of improving the dispersity of nickel fiber and the electromagnetic interference (EMI) shielding effectiveness (SE) of cement based composites. This study aimed of test the EMI SE of cement based composites in 1-1500Â MHz of the frequency range by coaxial cable method. The conductivity of cement based composites was test by four-point probe meter. The uniformity distribution of nickel fiber, silica fume and colloidal graphite was characterized by scanning electron microscopy. The results obtained indicate the nickel fiber has great effects on the EMI SE of cement based composites. With the content of nickel fiber was increased, the EMI SE of the composites were gradually increasing. When the nickel fiber was doping by 9.0 vol.%, the average SE of cement composites was reached 21.78Â dB, the maximum SE was 24.48Â dB in 120Â MHz. When 20 wt.% of silica fume and 9.0 vol.% of nickel fiber were added in a cement matrix, the shielding property of the composite was best, the average SE was reached 30.13Â dB, the maximum SE was 35.50Â dB in 30Â MHz. The best EMI SE was achieved by the sample comprised of colloidal graphited 20 wt.% and nickel fiber 5.0 vol.%, as exhibiting the average SE was reached 45.0Â dB, the largest SE was 51.19Â dB at 1170Â MHz, indicating a synergistic effect of colloidal graphite and nickel fiber.
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Authors
Wei-lin Yao, Guoxuan Xiong, Ying Yang, Hai-qing Huang, Yu-fen Zhou,