Determination and extraction of Rayleigh-waves for concrete cracks characterization based on matched filtering of center of energy

Surface Rayleigh wave (R-wave) has been used to detect and characterize defects in concrete due to its unique propagation properties. However, the determination of R-wave component is still ill-defined. In the present paper, a finite difference wave equation is employed for the numerical simulations of a transient point source interacting with a surface-opening crack on concrete. The compression wave (P-wave) and R-wave components were extracted and identified based on a new algorithm that utilizes matched filtering of center of energy (MFCE) concept to correlate wave parameters with crack depth. Experimental excitation and acquisition of R-waves was then carried out on concrete block specimens with artificial surface-opening crack to verify the correlations obtained via simulations. Experimental results are found to be in good agreement with the numerical ones, justifying the feasibility of the proposed method to determine and extract R-wave components for use in estimating depths of concrete crack.