Electrical and Piezoresistive Properties of Steel Fiber Cement-based Composites Aligned by a Magnetic Field

Directionally distributed steel fiber cement-based composites (SFCCs) were prepared by magnetic field (MF) induction technology. The orientation factor of steel fibers in the as-obtained SFCCs was determined. Besides, the electrical resistivity and piezoresistive responses in two directions of aligned steel fiber cement-based composites, i e , parallel and perpendicular to MF, were measured. The effects of several variables, eg , steel fiber content, curing age, humidity, and temperature, on anisotropic electrical property were studied. The cyclic and failure piezoresistive responses in different directions were tested. It is found that the aligned steel fibers in the as-obtained SFCCs have a high orientation factor more than 0.88. Besides, SFCCs with aligned steel fibers exhibit an obvious anisotropic conductivity and piezoelectric sensitivity. The electrical conductivity of SFCCs with aligned steel fibers is less affected by temperature and humidity. At the steel fiber content of 2.5wt%, the piezoelectric sensitivity coefficient of SFCCs in the direction parallel to MF has the highest value of 324.14. In addition, the piezoresistive properties of SFCCs with aligned steel fibers in the direction parallel to MF indicate excellent sensitivity and stability under cyclic loading and monotonic loading.