Highly self-sensing cementitious materials towards smart infrastructure

To meet the requirement of the smart infrastructure, the preferentially oriented nickel-plated alumina fiber reinforced cementitious composites (NAFC) were fabricated via directional magnetic field (MF) induction which demonstrates remarkable self-sensing and self-diagnostic capabilities. The effect of various plating treatment on the deposition of nickel on the surface, the microstructure, compositional composition and arrangement characteristics of alumina fibers were investigated using X-ray diffraction (XRD), photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The four-phase method revealed that the NAFC incorporating 2.0 vol% Ni-AFs prepared at an optimal electroless plating temperature of 70 °C to yield a saturation magnetization of 22 emu/g achieved significantly lower electrical resistivity (10 5 Ω . cm) and highest FCR (13.77 %) under a parallel magnetic field alongside excellent hysteresis (9.5 %) and repeatability (2.5 %), a result directly attributable to the highly oriented fiber structure (average circularity: 0.88) induced by the magnetic alignment. This work demonstrates a novel and effective strategy for fabricating cementitious composites with designed anisotropic sensing capabilities, showing great potential for locating and monitoring damage in smart infrastructures. • Near-perfect magnetic alignment of Ni-AFs (circularity: 0.88) was achieved, enabled by an optimized Ni-coating (70 °C, 22 emu/g), creating a highly oriented microstructure in cement. • A synergistic mechanical and self-sensing performance peak at 2.0 vol% fiber content was realized, where the aligned structure enhances strength by 8–13 % and enables an ultra-high gauge factor of 673. • Unprecedented stability accompanies high sensitivity, with excellent signal repeatability (CV=2.5 %) and low hysteresis (9.5 %), overcoming the common trade-off in self-sensing composites. • The aligned network ensures superior conductivity and stable tunnelling conduction, reducing resistivity and providing a robust mechanism for reliable structural health monitoring.