Impact non-linear reverberation spectroscopy applied to non-destructive testing of building materials

Abstract

The development of non-destructive testing techniques to detect early micro damage in concrete and other building materials is important for efficient maintenance and management of existing infrastructure. Nonlinear acoustic methods have shown potential for the identification of early damage in brittle materials such as concrete. Commonly, these methods evaluate relative nonlinearity parameters from multiple resonance tests at different amplitudes. We demonstrate a recently developed alternative method, Impact Nonlinear Reverberation Spectroscopy (INRS), where quantitative nonlinearity parameters are evaluated from a single impact resonance test. The recorded reverberation of the measured signal is matched to a synthetic nonlinear damped signal. The proposed model allows instantaneous true physical amplitude, frequency, and damping of each mode to be characterized as a function of time, allowing for quantitative information of the nonlinear parameters. The hysteretic material nonlinearity can be quantitatively characterized over a notably wider dynamic range compared to conventional methods. Two examples from the application to concrete and stabilized soil are presented. In addition quantitative values of the hysteretic nonlinear parameter from stabilized soil samples are compared with the measured ultimate compressive strength of each sample.