The Experiment Research On The Viscoelastic And Damage Properties Of Asphalt Mixture Under Uniaxial Pressure

Asphalt mixture of high-grade road pavementis the main construction materials, years of research shows that it is a complex therm-flow of materials. Deformation and the force of their state relate to it's temperature,loading rate and other factors. It is obvious anisotropy, heterogeneous and discontinuity. it is compli- cated nonlinear nature. Asphalt mixture under the load circumstances often show significant non-linear viscoelastic nature. Analysis of its the mechanics are often limited to the study of viscoelastic in the past, so its good mechanical properties are not activety.Viscoelastic theory is in mechanical and materials developed between the Bianyuankexue, and it serve impartial part of continum mechanics. At present, domestic and foreign scholars in the field of viscoelastic theoretical research has made many important research progress of viscoelastic theory,and it has been developing better,but the non-linear viscoelastic theory and mathematics because of it's difficulties is still in the continuous development and improvement of Way.This paper carried out some tests researches on the viscoelastic properties and damage properties of asphalt mixture under uniaxial pressure. The asphalt mixture selected for the tests are AC-13 and SMA-13, and the asphalt is 90#.The result of road performance tests of AC-13 and SMA-13 indicated that their properties of high temperature stability,water stability,low-temperature cracking and fatigue performance can meet the specifications of construction technology. Besides, all the data indicators of SMA-13 significantly preceded those of AC-13.The result of static creep test of SMA-13 and AC-13 indicated that the flow deformation of viscosity of asphalt mixture does not unlimitly increase with the load time prolongs. As time goes by, the increment of flow deformation of viscosity decreased gradually and caused the flow deformation of viscosity to incline a stable value ultimately, which is so-called "consolidation effect". Moreover, under the same conditions, SMA has a stronger anti-deformation ability than AC. According to the flow characteristics of asphalt mixture, this paper proposed a comparatively desirable and useful creep compliance model. Directed towards the static creep test curve, this paper used a constrained optimization methods to determine some concerned parameters of the model. According to the stress controlled fatigue test results of SMA-13 and AC-13, this paper made the fatigue cycle number and the corresponding cycle number non-dimensional and used the Levenberg-Marguardt Nonlinear Least Square Method to define damage by the variation of modulus. Then, this paper could conclude the non-linear evolution model equations of fatigue damage of AC-13 and SMA-13 through the fitting method, which could preferably simulate the fatigue damage evolution process of asphalt mixture.