Non-linear ultrasonic defectoscopy of concrete structures for nuclear industry

Concrete structures exposed to neutron radiation may exhibit cracking and deterioration, therefore it is needed to find appropriate non-destructive testing methods for assessing their structural integrity. Non-linear wave modulation spectroscopy (NWMS) was developed for non-destructive detection of cracks inside concrete. The goal of this paper is to compare the results of conventional non-destructive and destructive testing methods to the proposed non-linear NWMS method applied to ordinary concrete samples. The concrete damage by neutron radiation was simulated by thermal loading of the samples. Ultrasonic impulse method, resonance method, non-linear wave modulation method, compressive strength and flexural strength testing methods were applied.