Studies On Permanent Deformation Of Asphalt Mixture Based On Non-linear Creep Equation

Rutting is one of the major failures of asphalt pavement, and it severely influences the safety and comfort of the running vehicle with the development of highway, it is very important to study the rutting problem for asphalt pavement. Although scholars have studied new materials, grading composition design methods, evaluation methods and rutting prediction to improve rutting resistance of asphalt pavement, rutting still exist. The existing asphalt mixture creep models can not completely and accurately reflect asphalt pavement permanent deformation, and asphalt mixture evaluation methods of high temperature properties can not accurately reflect resistance to permanent deformation of asphalt mixture. Therefore, this article uses nonlinear viscoelastic rheological model theory to study evaluation method of high temperature performance of asphalt mixture, mainly including the following:Firstly, by studying the model theory of viscoelastic mechanics and creep curve's character in asphalt mixture, make sure a typical deformation curve should consist of three stages, that is, decaying creep stage, stable(constant velocity) creep stage and accelerated creep stage. Based on this, brought forward a non-linear rheological element which described accelerated creep stage accurately and established a seven parameters viscoelastic which is applicable for describing permanent deformation's character of asphalt mixture. For the proposed nonlinear seven parameters viscoelastic model, a series of researches are carried out based on test results to further analysis of their functional properties. Through unxial repeated loading creep test, calculated and validated it. And then, carried out theoretical study of finite element realization on creep model.Secondly, based on nonlinear viscoelastic model, established 17 kinds of typical viscoelastic parameters of asphalt mixture and studied evaluation method high temperature performance of asphalt mixture. In addition, used single factor and two-factor perturbation sensitivity analysis method to carry out sensitivity analysis of viscoelastic parameters on dynamic stability DS in order to seek sensitive viscoelastic parameters on high-temperature performance of asphalt mixture, then provided a theoretical basis for improving high temperature properties of asphalt mixture.Finally, study permenant deformation characteristics of asphalt mixture structure under the wheel load by monitoring the strain within the structure using FBG strain sensors for asphalt mixture. So that provide a theoretical foundation for the applications of seven parameters creep model.A series of creative researches, such as asphalt mixture creep model theory, numerical simulation of creep model, high-temperature performance evaluation and permenant deformation of asphalt mixture, were carried out in this paper. These researches will promote the development of the anti-rutting of asphalt pavement.