Material Composition And Structure Study Of Ultra-thin Asphalt Concrete Pavement In Wuhan

Asphalt pavement is one of the high-grade pavements which is widely used in current road construction.With the increase in the volume of traffic and overloading of vehicles,there are still many problems emerge in the construction of asphalt pavement,which affects pavement performances. As new pavement material, ultra-thin asphalt mixture has been widely used abroad currently with good performances such as less thickness, good skid resistance, low noise, evenness and so on.In our country,it has been done a preliminary research.According to the theoretical knowledge,this paper starts with the analysis of the composition structure of thin asphalt mixture and formation mechanism.Then ultra-thin asphalt concrete mixing ratio design is studied through the indoor test.At last, the mechanical response of thin asphalt concrete structure is analyzed using finite element software,and the influence on the various indicators of the structure is also discussed in detail with variations of different pavement material parameters (thickness, modulus).As shown in the study, ultra-thin asphalt concrete is dense mixture with broken gradation and skeleton-dense structure.The test data shows that both the gradation mixtures of SMA10 and SAC10 can meet the indicators requirements of Marshall test,and the best combination of material is diabase,SBS modified asphalt and cement.In addition,based on the results of finite element analysis,the surface deflection of the pavement structure has bigger values in the loading area;the maximum principal of the bottom layer appears at sub-base;the maximum shear stress in different locations is complex;the closer to the surface,the more complex of the changes;compared with the change of thickness,the change of modulus has more obvious impacts on the indicators of the structure;the change of underside modulus obviously affects the maximum principal of underside and sub-base;the change of surface modulus contributes to the apparent variation of the maximum shear stress in different locations.