Review of evaluating asphalt pavement structure integrity and strength with Rayleigh wave Methods: Techniques, Applications, and trends

•Introduces theories related to Rayleigh wave in pavement inspection.•Highlight the main findings of Rayleigh wave in pavement inspection.•Motivations, challenges and issues in applying Rayleigh waves to pavement assessment.•Present research gaps and provide options for other interested researchers. To maintain optimal serviceability and control maintenance costs, regular inspections of pavements are vital. Compared to other non-destructive methods, Rayleigh wave techniques are particularly effective in evaluating layered materials and show significant potential and advantages in assessing road pavements. This method not only provides modulus variation with depth but also reveals pavement crack distribution with higher precision. Moreover, it can detect in-situ damage and predict impending cracks. This paper, presents a comprehensive summary of Rayleigh wave methods, including their processes, principles, frequency dispersion curve extraction methods, forward methods, and inversion methods. The application of Rayleigh waves in pavement assessment is also illustrated, covering the thickness and moduli of each layer and the distribution and development status of internal cracks. Furthermore, the paper highlights challenges, trends, and future perspectives of Rayleigh wave techniques in asphalt pavement evaluation.