Nondestructive Characterization of Field Damaged Asphalt Pavement Using Ultrasonic C-Scan: Anisotropy and Traffic Effects

This chapter presents the findings from an experimental study using ultrasonic wave velocity (UWV) testing on a field asphalt mix in the form of plates. These plates were extracted from trafficked and nontrafficked zones in order to evaluate traffic effects on residual mechanical properties. The signal processing emphasis involves methods for determining time of flight (TOF) as a function of signal-to-noise ratio (SNR). The data are depicted through spatial cartographies, followed by statistical analysis to assess the spatial distribution homogeneity of velocities and mechanical properties. To quantify the anisotropy of field samples, the plates were shaped into parallelepipeds, and residual mechanical properties were measured in three spatial directions. The effectiveness of the ultrasonic method in characterizing and quantifying the anisotropy of asphalt concrete samples is demonstrated.