| abstract |
The damage evaluating apparatus 1 is installed on a concrete structure in which a tendon 10 to be damaged is to be evaluated and is used. The damage evaluating apparatus 1 includes a magnetizer 20 for generating a magnetic force, and a tenton And detectors 41F, 41R, and 61 for detecting the amount of change of magnetism generated from the damaged portions of the magnetic sensors 10A and 10. The magnetizing device includes an exciting coil 24, an iron core 26 penetrating the center hole of the exciting coil, a pair of columnar yokes 31F and 31R connected to both ends of the iron core and extending toward the concrete surface, And a pair of plate-like yokes (32F, 32R) connected to each of the ends of the pair of column-like yokes to form a magnetic pole having an extension along the concrete surface. By flowing a current to the exciting coil, a magnetic circuit is formed by the tendons in a range located between the yoke shaft, the pair of column-shaped yokes, the pair of plate-shaped yokes, and the pair of plate-shaped yokes. |