Rutting Prediction Of Asphalt Pavements In The Long Upgrade Under The Heavy-load And Low-speed

Asphalt mixture of permanent deformation (rutting) is a flexible pavement of one of several main forms of damage. The using of rutting directly reduces the capability of pavement so that the pavement will be seriously damaged along with the rutting depth is continuously accumulated. This damaging pavement phenomenon is particularly conspicuous in the long upgrade road. Therefore, it is necessary to have a reasonable forecast toward rutting in the recent design and management of the pavement in our country.In this paper, take the A4 contract of Ya-Lu freeway as research object, it found a new way to forecast for the rutting and calculate the forecast result. The upper layer material of the section of asphalt pavement structure is SMA13 modified asphalt (4cm), the middle layer material is AC20 alkylic asphalt plus 0.3% anti-rutting additive (5cm), the bottom layer material is A20 alkylic asphalt (6cm).This discourse introduces the Burgers viscoelastic constitutive equation and the establishment of a rutting testing load model. It deduces the permanent deformation calculation of single-rutting specimen under cyclic loading based on the integral-type creep constitutive equation (Boltzmann superposition principle of integral-type). In the second place, consider the aim of Lu-Ya freehway project, the tester has been improved base on the rutting test instrument of Japan. It tests under a different frequency of load, a different load level and a different temperature and collect the deformation data in the whole process of test. It constitute a calculate model for lab rutting test by ANSYS software, use the model to anti-calculate the viscoelastic material parameters and checkout them. Finally , combined with the traffic information of A4 contract of Ya-Lu freeway, it designs a combination of axle load order, correct the load size and time, deduces the rutting deformation equation in the actual pavement under the combination of axle load group based on the Boltzmann superposition principle, and write the calculation software to forecast its rutting.