Characterizing concrete surface notch using Rayleigh wave phase velocity and wavelet parametric analyses

A multichannel Rayleigh wave (R-wave) measurement technique is proposed for evaluating concrete surface notches with different orientations. In this study, numerical simulations were first conducted to examine the propagation of R-waves in steel-reinforced concrete comprising of surface notch inclining at 30°, 90° and 150° against the horizontal plane. The change of R-wave amplitude was obtained through analysis by wavelet transform (WT) and fast Fourier transform (FFT) for determining theirs correlations with the notch depth-to-wavelength ratio. Experimental measurements on concrete samples were then carried out to validate the proposed technique and its performance, particularly for cases where notch depth is greater than R-wave wavelength. Good agreement was found between the experimental results and the numerical calculations, offering good possibility for using R-waves to assess vertical and inclined surface notches in reinforced concrete with the proposed technique for R-waves acquisition and analysis.