Accurate determination of near-surface responses of asphalt pavements

Abstract

Accurate determination of structural responses plays a critical role in a mechanistic-empirical pavement design. A new distress model, top-down fatigue cracking, has been incorporated in the newly developed Mechanistic-Empirical Pavement Design Guide. The critical response for top-down cracking is the horizontal tensile stress or strain at the pavement surface. However, the poor convergence of analytical layered elastic solutions in the vicinity of the pavement surface may result in large errors in response results. This study uses the Lucas algorithm to effectively solve this problem. The algorithm converts the complicated oscillating behaviour of the product of Bessel functions to regular oscillations by separating the integrand into high- and low-frequency components. Thus, extrapolation techniques can be effectively applied to accelerate the convergence. A computer code is developed to implement the proposed procedure. The computer code is verified against the boundary conditions and finite element results. It is also compared to other layered elastic programs. The results show that the proposed procedure can accurately determine the near-surface responses of asphalt pavements.