Electromagnetic shielding properties of carbon fibre reinforced cementitious composites

Wanasinghe, Dimuthu; Aslani, Farhad; Ma, Guowei

doi:10.1016/j.conbuildmat.2020.120439

Cited by 45 publications

(27 citation statements)

References 86 publications

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“…Conductivity (S/cm) 10 6 10 3 1 10 -3 10 -6 10 -9 10 -12 ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ ꟾ Fig. 11.…”

Section: Discussionunclassified

An analysis of effect of water hyacinth carbonization temperature on fabrication and EMI shielding radar

Imammuddin

Suparman

Suprapto

et al. 2021

EEJET

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The need to increase the ability of water hyacinth composites as EMI radar protection is related to the carbonization process of organic materials. This research aimed to determine the effect of water hyacinth carbonization temperature on the effectiveness of fabrication and EMI shielding radar. The research method includes the preparations such as cutting, washing, and drying the water hyacinth. The drying process is carried out using an oven with a temperature of 70 °C for 4 days. Then the water hyacinth is mashed until it reaches the 80 mesh size. Then the carbonization process is carried out, with variations in carbonization temperature ranging from 500 °C, 600 °C, 700 °C, 800 °C, 900 °C and 1,000 °C, with a heat increase speed of 3 °C/minutes. After reaching the specified temperature, a holding time is then carried out for 1 hour. Furthermore, the composite composition of 30 % water hyacinth activated carbon powder and 70 % phenol-formaldehyde (PF) resin was molded using a hot press with a pressure of 300 kg/cm2 at 180 °C for 10 minutes. The results showed that the water hyacinth composite could be used as an EMI protection material at the X-Band frequency (8–12.5 GHz). Where the electrical conductivity and EMI SE increases with increasing carbonization temperature. Water hyacinth composites at a carbonization temperature of 1,000 °C showed the highest electrical conductivity and the highest EMI SE, respectively 4.64∙10-2 S/cm and 41.15 dB (attenuation 99.99 %) at a frequency of 8 GHz. The high absorption contribution is associated with the synergy combination of KCl and the pore structure of the goitre. KCl contributes to the magnetic properties and pore structure with high electrical conductivity values

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Section: Discussionunclassified

An analysis of effect of water hyacinth carbonization temperature on fabrication and EMI shielding radar

Imammuddin

Suparman

Suprapto

et al. 2021

EEJET

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“…This indicates that when conductive fibers were added into concrete with very low conductivity, the shielding effectiveness increased abruptly at a low content owing to the formation of a conductive network, but the shielding effectiveness leads to the saturation level when a percolation conductive network is approached owing to the increased content. A previous study also reported that the addition of conductive fibers into cementitious materials results in an abrupt improvement in conductivity and electromagnetic shielding performance, but the improvement effect according to the increased content decreased beyond a certain content [40]. In addition, it was reported that an increase in the length or aspect ratio of the conductive fibers is favorable for forming a conductive network and improves the electromagnetic shielding effectiveness [19,41,42].…”

Section: Electromagnetic Shielding Effectivenessmentioning

confidence: 95%

Electromagnetic Wave Shielding Properties of Amorphous Metallic Fiber-Reinforced High-Strength Concrete Using Waveguides

Lee

Kim

et al. 2021

Materials

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In this study, high-strength concrete containing hooked-end steel or amorphous metallic fibers was fabricated, and the electrical conductivity and electromagnetic shielding effectiveness were evaluated after 28 and 208 days based on considerations of the influences of the moisture content. Amorphous metallic fibers, which have the same length and length/equivalent diameter ratio as hooked-end steel fibers, were favored for the formation of a conductive network because they can be added in large quantities owing to their low densities. These fibers have a large specific surface area as thin plates. The electromagnetic shielding effectiveness clearly improved as the electrical conductivity increased, and it can be expected that the shielding effectiveness will approach the saturation level when the fiber volume fraction of amorphous metallic fibers exceeds 0.5 vol.%. Meanwhile, it is necessary to reduce the amount of moisture to conservatively evaluate the electromagnetic shielding performance. In particular, when 0.5 vol.% of amorphous metallic fibers was added, a shielding effectiveness of >80 dB (based on a thickness of 300 mm) was achieved at a low moisture content after 208 days. Similar to the electrical conductivity, excellent shielding effectiveness can be expected from amorphous metallic fibers at low contents compared to that provided by hooked-end steel fibers.

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“…The electrical conductivity of NC-SS15 increased by approximately 29% compared to that of NC-NN. Additionally, Fe 2 O 3 in the steel slag absorbed the EM waves, and steel slag slightly improved EM shielding [8]. The effect of the lightweight coarse aggregate on the shielding effectiveness was analyzed by comparing NC-SS15 and LC-SS15.…”

Section: Shielding Effectivenessmentioning

confidence: 99%

“…Overall, fiber-reinforced polymer rebars are non-conductive, but CFRP rebars contain carbon fiber, increasing conductivity; thus, CFRP and steel rebars exhibit similar conductive behavior. Several researchers [8,10,54] found that the conductivity and shielding effectiveness improved with the carbon fiber content. Figure 10b shows a comparison between the C100 and C50 series, in which CFRP rebars were arranged at spacings of 50 mm.…”

Section: Shielding Effectivenessmentioning

confidence: 99%

“…EM waves react with the electric charge when they are incident on concrete, and the microcurrent flows instantaneously. This reaction induces electrical resistance loss, and the concrete eventually absorbs the EM waves [4,[6][7][8]. Some researchers [9][10][11] reported that the better the electrical conductivity of concrete, the better the shielding effectiveness.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical and Electrical Characteristics of Lightweight Aggregate Concrete Reinforced with Steel Fibers

et al. 2021

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There is increased interest in applying electromagnetic (EM) shielding to prevent EM interference, which destroys electronic circuits. The EM shielding’s performance is closely related to the electrical conductivity and can be improved by incorporating conductive materials. The weight of a structure can be reduced by incorporating lightweight aggregates and replacing the steel rebars with CFRP rebars. In this study, the effects of lightweight coarse aggregate and CFRP rebars on the mechanical and electrical characteristics of concrete were investigated, considering the steel fibers’ incorporation. The lightweight coarse aggregates decreased the density and strength of concrete and increased the electrical conductivity of the concrete, owing to its metallic contents. The steel fibers further increased the electrical conductivity of the lightweight aggregate concrete. These components improved the EM shielding performance, and the steel fibers showed the best performance by increasing shielding effectiveness by at least 23 dB. The CFRP rebars behaved similarly to steel rebars because of their carbon fiber content. When no steel fiber was mixed, the shielding effectiveness increased by approximately 2.8 times with reduced spacing of CFRP rebars. This study demonstrates that lightweight aggregate concrete reinforced with steel fibers exhibits superior mechanical and electrical characteristics for concrete and construction industries.

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Electromagnetic shielding properties of carbon fibre reinforced cementitious composites

Cited by 45 publications

References 86 publications

An analysis of effect of water hyacinth carbonization temperature on fabrication and EMI shielding radar

An analysis of effect of water hyacinth carbonization temperature on fabrication and EMI shielding radar

Electromagnetic Wave Shielding Properties of Amorphous Metallic Fiber-Reinforced High-Strength Concrete Using Waveguides

Mechanical and Electrical Characteristics of Lightweight Aggregate Concrete Reinforced with Steel Fibers

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