Simultaneously enhanced mechanical and electromagnetic interference shielding properties of steel slag-recycled carbon fiber cementitious composites via wet-grinding process

This study aims at investigating the mechanical and electromagnetic interference (EMI) shielding properties of cementitious composites with combined utilization of recycled carbon fiber (rCF) and steel slag. Different dosage of raw steel slag (SS) and wet-grinding steel slag (WSS) as replacement of cement were introduced to the cementitious composites with rCF. Wet-grinding can enhance hydration activity of SS, and also can improve the dispersibility of rCF in cement matrix thus optimizing the mechanical properties. The electrical resistivity of the composites decreases with increased WSS dosage, the conductive phase in WSS not only form new conductive pathways, but also act as bridges to connect rCFs, the WSS is more effective in lowering the electrical resistivity. The shielding effectiveness (SE) of the rCF-WSS cementitious composites increases with increased WSS dosage, which is higher than that of SS due to the higher conductivity and scattering effect of reduced particle fineness. The absorption loss SEA dominates the SET, which is mainly attributed to increasing electrical conductivity, the dielectric loss and magnetic loss also contribute to absorption loss. The synergistic effect of rCF and steel slag on electrically conductive and EMI shielding properties was demonstrated, wet-grinding process can promote the synergistic effect.