This study developed the multifunctional ultra-lightweight engineered cementitious composite (ULW-ECC) by integrating conductive fillers to achieve effective electromagnetic interference (EMI) shielding capabilities, outstanding mechanical properties and thermal insulation. The mechanical performance, electrical conductivity, EMI shielding effectiveness (SE), and microstructure were analysed. Initially, the effects of the carbon fibre (CF) content and the pre-heating temperature of CF on EMI SE of the matrix (named: ULW-CC) without polyethylene (PE) fibre were tested. Then, CFs (0.5 and 1.0 vol%) with seven lengths (1–20 mm) were respectively incorporated into ULW-ECC to study EMI SE. The EMI SE of ULW-ECC incorporating powder calcined petroleum coke (CPC) was compared with that of CF. Experimental results demonstrated that the incorporation of conductive fillers improved the strength, conductivity, and EMI SE. Both the conductivity and EMI SE of ULW-CC and ULW-ECC increased with the dosage of conductive filler. EMI SE was enhanced with increased electrical conductivity, and pre-heating CF at 300 °C further improved the EMI SE. In ULW-ECC, 9-mm CF showed the highest EMI SE and conductivity. The conductivity and EMI SE of ULW-ECC were lower than those of ULW-CC at the same CF dosage due to the negative impact of PE fibre dispersion on the conductive network of CFs. The mixing method of CF in ULW-ECC affected the EMI SE. The EMI SE of ULW-ECC incorporating powder CPC was much lower than that incorporating CF, but hybridization of CPC and CF significantly enhanced EMI SE.

中文翻译：

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用于电磁干扰屏蔽的多功能超轻工程水泥基复合材料 （ECC）


本研究通过集成导电填料开发了多功能超轻工程水泥基复合材料 （ULW-ECC），以实现有效的电磁干扰 （EMI） 屏蔽能力、出色的机械性能和隔热性。分析了机械性能、导电性、EMI 屏蔽效果 （SE） 和微观结构。最初，测试了碳纤维 （CF） 含量和 CF 的预热温度对不含聚乙烯 （PE） 纤维的基体（命名为：ULW-CC）的 EMI SE 的影响。然后，将具有 7 个长度 （1–20 mm） 的 CFs （0.5 和 1.0 vol%） 分别掺入 ULW-ECC 中以研究 EMI SE。将加入粉末煅烧石油焦 （CPC） 的 ULW-ECC 的 EMI SE 与 CF 的 EMI SE 进行了比较。实验结果表明，导电填料的加入提高了强度、导电性和 EMI SE。ULW-CC 和 ULW-ECC 的电导率和 EMI SE 均随着导电填料的用量而增加。EMI SE 随着导电性的增加而增强，在 300 °C 下预热 CF 进一步改善了 EMI SE。在 ULW-ECC 中，9 mm CF 显示出最高的 EMI SE 和电导率。由于 PE 纤维分散对 CFs 导电网络的负面影响，ULW-ECC 的电导率和 EMI SE 在相同 CF 剂量下低于 ULW-CC。ULW-ECC 中 CF 的混合方式影响了 EMI SE。掺入粉末 CPC 的 ULW-ECC 的 EMI SE 远低于掺入 CF 的 ULW-ECC 的 EMI SE，但 CPC 和 CF 的杂交显著增强了 EMI SE。