Abstract
Recently, it is strongly required to give concrete structures a longer life by means of the proper control of maintenance. As for the control, it is necessary to evaluate the soundness and quality of concrete structures. Among nondestructive tests for the evaluation, an ultrasonic wave method has high detection accuracy for defects in a material. In this study, numerical analyses are conducted with considering the degradation and cracking occurred by an alkali-silica reaction to check the applicability of an ultrasonic wave method, above all a surface method. It is turned out that the amplitude of the wave decreases through deteriorated area around an aggregate, and that a reflective wave across a crack is visible in a response displacement at a receiver. In conclusion, the possibility that the surface method seizes the defects in concrete structures is shown.
