Determination of Surface Viscoelastic Response of Asphalt Pavement

Abstract

Asphalt concrete exhibits rate- and time-dependent behavior, and therefore viscoelastic response analysis is necessary to model the pavement structure behavior and explain the distress mechanisms. The newly developed Mechanistic–Empirical Pavement Design Guide emphasizes the importance of accurate determination of response at the pavement surface to efficiently model the top-down cracking and implement the sublayering scheme. However, it is shown in this study that the integrand of the Laplace-transformed step-response function at the pavement surface exhibits complicated oscillating behavior and slow convergence, making it difficult to achieve accurate viscoelastic solutions. This study proposes a procedure to effectively solve this problem. The proposed procedure uses the Lucas algorithm to reduce the complex oscillations to regular oscillations by separating the integrand into high- and low-frequency components and then uses integration, summation, and extrapolation methods to accelerate the coverage. The results obtained from the proposed procedure are extensively verified against the boundary conditions and finite-element results. The verification results show that the proposed procedure can accurately determine the surface viscoelastic response and provide an effective tool for pavement analysis and design.