Coda wave interferometry (CWI) is a novel non-destructive method for monitoring the integrity of concrete structures. It is highly sensitive to even weak material changes, making it an effective early warning system for potential damage. By comparing two ultrasonic waveforms, CWI identifies velocity shifts in the late-arriving coda waves, particularly in heterogeneous media where scattering occurs.
This study analyzed the effects of temperature, humidity, and stress on coda wave velocity by means of the stretching method, identifying linear and non-linear relationships. Long-term phenomena such as shrinkage and creep were also characterized. Following the conducted experiments, an additional model was developed to further enhance the understanding of these factors and their impact on concrete over time.