Study On Steady-state Behavior Of Asphalt Mixture And Its Application

The common form of the permanent deformation of the asphalt pavement is rutting. Asphalt mixture is the material for asphalt pavement, and the most effective way for reducing the harm of rutting is enhancing the asphalt mixture behavior. This paper focus on the steady-state behavior of asphalt mixture, and the main contents are given as follow1. At first, the uniaxial compression and creep tests are introduced in Chapter Two. There is a mechanical clearance in the uniaxial compress test; the clearances affect the datum and results of the tests significantly. Confirming the clearance by a compress test of steel sample, and a method to eliminate these mechanical clearances is introduced, which is valuable for doing the mechanical property testing of low modulus materials such as asphalt as a reference.2. Due to the result of the uniaxial compression and creep tests, the deformation characteristics of asphalt binder are studied in Chapter Three. The compressive strength reflects material under load capacity; it can be obtained from the uniaxial compress test. The interpolation relations of the compressive strength are given in this chapter by four factors: percent particle, particle size, and temperature and loading rate. And due to the creep test, some viscous-elastic models are studied in this chapter, it's show that Burgers Model can be fit the behavior of asphalt mixture better than other by the fitting results.3. Considered the asphalt mixture as a particulate-reinforced composite material, following the research path described by'Bitumen + Fine Aggregate = Asphalt Binder; Asphalt Binder + Coarse Aggregate = Asphalt Mixture', the initial modulus and mechanical behaviors of asphalt mixture are analyzes in Chapter Four.4. The viscoelastic model in the finite element software Abaqus by Prony series and the D-P model are introduced in Chapter Five, this chapter also formulate the user subroutine method (UMAT) of the viscoelastic model .The rutting is considered as the permanent distortion of Burgers Model in Chapter Six, this chapter calculates the parameters of Burgers Model by simplifying the road loading. This chapter use FEM to simulate the rutting experiment of asphalt mixture and consider the type of the load, it shows that the result of FEM is good fit the experiment when the load time is 1/4 of the full experiment time.