Fracture range detection in hydro-abrasive erosion of concrete

The paper discusses fast Fourier transform (FFT) parameters of acoustic emission signals acquired during the hydro-abrasive erosion (HAE) of five different concrete mixtures. The FFT-peak amplitude as well as the FFT-peak frequency shows some pronounced relationships to the depth of penetration and to the fracture behavior of the investigated materials. Correlation statistics is used to separate three distinguished fracture ranges during HAE: intergranular erosion, mixed-mode fracture, and transgranular fracture. It is concluded that FFT-peak amplitude and FFT-peak frequency of the acoustic emission signals can be used for the on-line control of HAE-processes.