Monitoring of compressive stress changes in concrete pillars using cross correlation

The use of ultrasound in structural health monitoring of concrete structures is an accepted technique. In recent years more sophisticated signal processing, like coda wave and cross-correlation of signals have been used. In this paper, we investigate different signal processing techniques of the coda wave signals in order to analyze the compression of a concrete pillar. Four metrics were compared, namely, the energy of the signal, the maximum of the correlation function, the time of correlation maximum and the symmetry around the maximum. Results are presented for different temporal windows.