Research On Designing Optimal Asphalt Content Of Asphalt Mixture Based On Road Performance

In the design process of asphalt mixture, the method of Marshall is commonly used to determine the optimal asphalt content, but it is based on the volume parameter, and the Marshall stability and flow value almost have nothing to do with the long-term road performance. In response to these issues, take AC-25 asphalt mixture for example, this article studies the influence of the asphalt content to road performance, analyzes the relativity between shearing strength of different tests and road performance, try to find some design method which is connected with the road performance.The paper studies the influence of the asphalt content to high temperature stability, low temperature crack resistance and water stability of asphalt mixture.Through the mechanical test,direct shear test and uniaxial penetration test, this paper analyzes the influence of the asphalt content to shearing strength, and studies the relativity of shearing strength with the road performace.Based on the above results, this paper uses the shearing strength of mechanical index method,direct shear method and uniaxial penetration method to determine the optimal asphalt content according to different road performance. Then the road performance of the three methods is tested, and the three methods compare to the Marshall method, finally, the method determining the optimal asphalt content according to road performance is developed.