Study On The Asphalt Mixture Design Optimization Based On Function Requirement

Xining city ring freeway is composed of the south ring freeway and the newly constructed crossing freeway. The construction of Xining ring freeway resolved the traffic crowded problems and provides the basis support of expanding the city and raising status. The asphalt pavements in Xining often appear deformation, cracks, ruts and other diseases which owns to AC-13 which plays the main place of asphalt mixture and the design can not satisfy regional requirements. The asphalt mixture design optimization must be applied to ensure excellent road performance. The key performance indicators and design parameters of asphalt mixture were researched, combined with Xining south ring freeway, aggregate gradation was balanced and preferred and the optimum asphalt ratio was defined. Based on the test road,performances of mixture were verified and the technical guidance was provided.(1)The influence of aggregate gradation to the performance of asphalt mixture were analyzed. Based on the key indicators of each surface layer, the technical requirements were provided,the design methods and key parameters of aggregate gradation were studied and the best choice was put forward.(2)Base on hyperbolic model,,the results of Super pave test,Bailey method, Marshall test and the performance-based test were compared. The aggregate gradation composition of ATB-25,AC-20 and AC-13 were defined.(3)The four methods to determine the best aggregate ratio of asphalt mixture design were analyzed, the best method was provided and the aggregate ratio of ATB-25,AC-20 and AC-13 were defined.(4)The substantial projects and quality tests were presented, the research results' feasibility of material selection, the balance of aggregate gradation and optimum asphalt ratio were demonstrated.