Comparative study of nonlinear resonance and wave interaction techniques for concrete damage assessment

Abstract

Two nonlinear parameters extracted from different approaches have been compared on their sensitivity and reliability to detect thermal damage in concrete. One approach is based on nonlinear resonance while the other relies on wave interactions. Results show that both nonlinear parameters have a sensitivity to thermal damage of the same order of magnitude. Variations observed are much higher than in the case of linear parameters (ultrasonic pulse velocity and dynamic modulus). Coefficients of variation showed that resonance frequency technique is more reliable than wave interaction technique. However, the latter technique remains of great interest and needs further developments since it is more adapted to in situ measurements. © RILEM 2013.