Improved piezoresistivity of cement-based composites filled with aligned nickel powder

This paper proposes a magnetic field (MF)-induced nickel powders-based alignment method to modify and optimize the electrical properties and piezoresistivity of the composites. The alignment of nickel powders by a MF results in the composites possessing a strong anisotropic conductivity. However, the strain gauge factor of the composites filled with nickel powders at percolation threshold content increases with MF strength. Furthermore, the strain gauge factor of the composites filled with randomly distributed nickel powders is strongly dependent on the Poisson ratio (transverse strain) of the composite, and this dependency is significantly reduced by aligning the nickel powders, indicating that the strain gauge factor of the cement-based composites filled with aligned nickel powders will be more stable and reliable when practically applied, even under complex strain states.