Journal of Nondestructive Evaluation

, Volume 13, Issue 1, pp 23–32 | Cite as

Magnetic imaging of reinforcing steel

  • Geneviève F. Pla
  • Marc O. Eberhard
  • Philippe H. Eberhard


A new nondestructive evaluation technique is proposed to image steel reinforcement in reinforced concrete structures. One imposes a static magnetic field on a reinforced concrete member and measures the distortion of that field due to the magnetization of the reinforcement. The distribution of magnetization within the member is determined by inverting linearized fundamental equations of magnetostatics. A second set of equations, involving the ambient magnetic field and the magnetic susceptibility of steel, relates the magnetization to the volume of steel. Simple finite-element simulations were performed to investigate the performance of the reconstruction algorithm. The present version of the algorithm differentiated clearly between widely-spaced cubes of steel and air. The reconstructions were less successful when the cubes were adjacent. Some areas that deserve further development were identified. The magnetostatic principles underlying the imaging technique could also be applied to locate ferromagnetic objects for other applications.

Key words

Imaging nondestructive evaluation magnetism reinforcing steel 


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Copyright information

© Plenum Publishing Corporation 1994

Authors and Affiliations

  • Geneviève F. Pla
    • 1
  • Marc O. Eberhard
    • 1
  • Philippe H. Eberhard
    • 2
  1. 1.Department of Civil Engineering More HallUniversity of WashingtonSeattle
  2. 2.Lawrence Berkeley LaboratoryBerkeley

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