Effect of constitutive relationship of asphalt mixture on pavement response

In order to provide reference for the analysis and design of asphalt pavement, pavement responses of typical asphalt pavement structures were analyzed using three-dimensional finite element method. Asphalt mixtures were treated as viscoelastic materials and elastic materials whose mechanical properties were represented by dynamic modulus and compressive resilient modulus. Surface deflections, horizontal stresses at the bottom of asphalt layer and semi-rigid base were calculated at various temperatures and vehicle speeds for different base types. The results show that pavement responses obtained through dynamic modulus are close to those through viscoelastic analysis, especially the average relative errors of the peak values of surface deflection and horizontal stress at the bottom of semi-rigid base are within 2%. The results through compressive resilient modulus are significantly different, especially the peak value of horizontal stress at the bottom of asphalt layer is only one-third of that through viscoelastic analysis. Dynamic modulus, instead of compressive resilient modulus, should be used in elastic analysis of asphalt pavement structure in order to achieve accurate results and the effects of temperature and vehicle speed should also be taken into account.