The failure of pavement near its surface (rutting and cracking) is a complex phenomenon affected by vehicular loading and pavement structure. This paper documents the investigation of near-surface failure in thick asphaltpavement using a developed 3-D finite element (FE) model and Mohr-Coulombfailure criterion. The FE model incorporates measured 3-D tire-pavement contact stresses, hot-mix asphalt (HMA) linear viscoelasticity, continuously moving load, and implicit dynamic analysis. The multiaxial stress states(normal and shear stress) near the pavement surface under measured tire contact stresses and moving wheel load are presented. The failure potentialof pavement near the surface was evaluated by comparing the multiaxial stress states predicted from the FE model to the Mohr-Coulomb failure criterion. The authors suggest that the cracking could initiate at the pavement's surface within the area between dual tires. This paper presents several conclusions about surface-initiated cracking potential: 1) It increases asthe temperature increases. 2) At high temperatures, the shear-induced surface cracking could initiate from some distance below the pavement surfacein conjunction with the distortional deformation. 3) Compared to the 3-D tire contact stress, the uniform contact stress distribution underestimates the pavement failure potential near the surface, especially at high temperatures. 4) The negative temperature gradient in the HMA layer induces a greater failure potential at pavement near-surface compared to the constant average temperature case. 5) The debonding under the surface layer significantly increases the shear stress at relatively low normal stress and leads to premature failure around the interface compared to the full bondingcase.
Samenvatting