Research On The Stress Caused By Load And Temperature In Asphalt Overlays By 3-DFEM

The reflective cracking easily appears in asphalt overlays on existing concrete pavements because of expansion joint and construction joint existed in the old surface. Through the study methods such as survey in the world, theoretical research and finite element analysis, adopting the three-dimension finite element model, detailed analysis of stress condition in joint area of overlay is given. Many factors to effect on reflection cracking is studied. On this base, the paper put forward the best base course, discussed the impact of asphalt rubber interlayer and the effect on reflection cracking if the area of joint is loss of support, analyzed the function of the thickness of asphalt overlay. IF the stress caused by temperature load is analyzed by the contact model of Goodman-hypothesis or orthotropic, the machanics model will be distortion. The paper adopted the contract model according with the fact, studied the effect of contract condition on reflection cracking, analyzed the main factor of reflection cracking caused by temperature changes. Many prevention measures were adopted to prevent and stave the reflection cracking in the asphalt overlay on existing concrete pavements in the world. The paper introduced many main prevention measures, and compared them. A theoretical basis is provided for improving the method of asphalt overlays on existing concrete pavements.