Exploiting spectral differences between two acoustic imaging methods for the in situ evaluation of surface-breaking cracks in asphalt

Abstract

The assessment of the location and the extension of cracks in roads is important for determining the potential level of deterioration in the road overall and in the infrastructure buried beneath it. Damage in a pavement structure is usually initiated in the tarmac layers, making Rayleigh waves ideally suited for the detection of shallow surface defects. Assessment of crack in roads is usually performed assuming constant velocity and non-dispersive behaviour of the material tested, limiting this approach to the very shallow layer of the road. In this work, differences between the spectral images obtained with the Multichannel Analysis of Surface Waves (MASW) and the Multiple Impact of Surface Waves (MISW) are exploited for the first time to detect, locate and evaluate

Thein-situevaluation of surface-breaking cracks in asphalt using a wave decomposition method

“…Compared to existing methodologies for in-situ, quantitative crack depth evaluation, like the one described in [23] , it is faster since it does not require a comparison between different spectral images.…”

“…Since the wave velocities are larger in models B, C and D, a different sampling frequency is chosen to respect the Courant-Friedrichs-Lewy condition (see section 3). Mechanical parameters, density and damping ratios have been chosen to be close to typical values of soils and asphalts, and are similar to those used in [22], [23], [30], [50]. The reflection coefficient is computed, for all the simulations, as the amplitude ratio of the negative going wave to the positive going wave at the reference node.…”

“…The finite depth of the surfacebreaking crack blocks the shorter wavelengths, allowing only the longer wavelengths to proceed, and hence acting as a low-pass filter. The reflections and the changes in the frequency bandwidth of a seismic signal at the surface, caused by the presence of the crack, are exploited for its detection and evaluation [22], [23] .…”

Diagnostics of asphalt pavement using elastic standing waves

“…Seismoacoustic methods are also widely used to diagnose road surfaces. Typically, these methods are based on the analysis of surface (Nazarian et al ., 1993; Baker et al ., 1995; Celaya and Nazarian, 2006; Li et al ., 2016; Iodice et al ., 2019) or body (Nazarian et al ., 1993; Baker et al ., 1995; Khazanovich et al ., 2005; Cassidy et al ., 2011; Hoegh et al ., 2011; Hoegh et al ., 2012; Li et al ., 2016; Freeseman et al ., 2018; Choi and Park, 2019; Salles et al ., 2019) waves, which are excited at the surface with the help of various dynamic sources (shocks, vibrators, etc). In addition, passive seismoacoustic methods based on the analysis of vibrations that occur at the road surface from uncontrolled sources, such as vehicles, running crowds, seismic activity, etc., have recently been developed.…”