Study on detection of steel bar in concrete with electromagnetic impact driving method

The authors devised a new detection method of measuring the location of a steel bar within concrete on the concrete surface through an electromagnetic impact driving method. Through this method, a steel bar within concrete is driven directly into vibration with occurred impulsive magnetic flux at a flat spiral coil set on the concrete surface. That is, a steel bar within concrete is regarded as a sound source. The location of a steel bar within concrete is determined by the measured propagation time within concrete of radiated sound from a steel bar and the sound velocity in the concrete block. The experiment on the detection of a steel bar at a depth of less than 25 cm under the concrete surface was performed. From these experimental results, this method is expected to be useful for the detection of a steel bar within concrete. Furthermore, the propagation characteristics of sound in the concrete block and driving conditions for a steel bar within concrete were also examined.