Directional-sequenced magnetic pulses: a novel method to improve the alignment index of steel fibers through homogeneous magnetic fields in cementitious composites

Directional-sequenced magnetic pulses (D-SMP) are a method to achieve a better alignment index of reinforcing steel fibers in Concrete with the same device at the same magnetic field. The optimal angles to apply the magnetic field are obtained through the analysis of the angular rotation of the fibers for a determined magnetic field and the Yield Stress (T0) of the matrix. The method has been studied for three commercial Hooked-end-fibers (HSFs) commonly used as reinforcement in cementitious composites in a transparent fluid with a similar T0 to that of cement composites. The efficiency of the D-SMP method is determined through directional statistics, setting the alignment index and the mechanical efficiency factor of the composite. The results obtained demonstrate that the D-SMP method results in a higher angular homogeneity of fibers, alignment index and efficiency factor than the use of a magnetic field in a single direction.