Concrete damage evolution analysis by backscattered ultrasonic waves

In the case of in situ non-destructive evaluation of concrete, the one side access and the lack of knowledge of structure depth often increase the difficulties to control the material. The backscattered ultrasonic waves' exploitation can be a solution. Scatterers present in the medium return information resulting from interaction with the incident wave. We study the modelling of the backscattered waves and their experimental measurement. The signal model is adapted to simulate the concrete damage incidence on the ultrasonic waves. The limits of its exploitation are deduced. Experimentally, concrete specimens were examined for five states of thermal damage. According to the model the backscattered waves' attenuation evolves with the damage. The sensitiveness of an ultrasonic indicator to microstructural evolutions is analysed.