抄録
In Japan, concrete slabs of highway bridges, especially ones constructed before 1970, have suffered fatigue damage due to repeated traffic loads. "Steel plate bonding method" has been widely used for over 30 years to strengthen damaged concrete slabs. In recent years, however, the repaired structures have also been damaged due to the debonding of adhesive resin between a steel plate and concrete. In this study, a laser based ultrasonic method is developed for remote inspection of bonded steel plates. Some results are obtained in a laboratory measurement of specimens, and are discussed in comparison with impact hammer method and numerical results. It is shown that the laser based method has a promising possibility of effective nondestructive evaluation for steel plate bonding of highway bridges.
