| Long-life asphalt pavement structure with high durability,without structural repair,low life cycle costs characteristics,has widely applicated in the United States and other countries,which has better effect.But the idea of realizing the long life needs the material of bottom asphalt layer has high performance,therefore,the anti fatigue layer between the asphalt layer and the base layer has been used to improve the durability of the road in foreign countries.As the level of axial load in our country is far greater than that of foreign countries,the anti fatigue layer material suitable for domestic long life pavement must has good performance and fatigue life.Epoxy asphalt has good comprehensive temperature stability,water stability and excellent anti fatigue performance,the application of which in steel bridge deck pavement shows that it has more excellent benefits than the SMA and SBS modified asphalt,but in the road engineering application is rare.Therefore,this paper focuses on a long life asphalt pavement structure with epoxy asphalt mixture anti fatigue layer,its research content includs the development of epoxy asphalt,mixture performance and fatigue life.This paper first formulates the control index and the design idea of the development of epoxy asphalt,then slects various types of materials from the function and cost of each component,through the contrast test analysis,ultimately determines the optimum composition,the proportion and the preparation process of the epoxy asphalt,meanwhile analyze and verify the tensile strength,elongation at break,time curve of viscosity.Based on the specificity of the anti fatigue layer and the epoxy asphalt,the paper determines the gradation and asphalt aggregate ratio through mix design.For the analysis of epoxy asphalt mixture construction application period,the paper determines the epoxy asphalt mixture optimum curing time,curing temperature,curing time and strike times.Moreover,the paper tests the performances of temperature stability,water stability,dynamic and static modulus and fatigue life of the epoxy asphalt mixture,and establish the dynamic modulus master curve,the fatigue life prediction equation and determines the fatigue limit.At the end,the paper analyze the effect of epoxy asphalt mixture anti fatigue layer on the thickness of the pavement structure and the fatigue life,and analyze the application in the engineering project.Epoxy asphalt developed in this paper is divided into A and B components,its tensile strength and elongation are 2.47 MPa,respectively,265%,its time of the viscosity increasing to 1Pa·s is 54 min,which can meet the requirements of the performance index and the application for the construction period.The paper determines that the epoxy asphalt mixture gradation is AC-13,void ratio is less than 3% and asphalt aggregate ratio is 6.4%.Test results show that the epoxy asphalt mixture has comprehensive and good performance,high dynamic and static modulus and longer fatigue life,the fatigue limit is 330??.Epoxy asphalt mixture used as anti fatigue layer can play a role in reducing the thickness of asphalt layer thickness,improving the fatigue life of pavement structure. |
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