Superpave Design Of Skeleton Compact AC-20C

With the development of transportation industry,higher requirements have been put forward for the use quality of road surface,and the requirements for the design of asphalt pavement have become higher and higher.It is imperative to design better gradation of asphalt mixture.There is an increasing demand for the application of skeleton dense structure.Superpave design method is a pavement design method introduced in the United States,and it is also widely used in China.However,Marshall design method is still used for AC series of common dense gradation asphalt mixture in China.Based on the project of Yanchong Expressway in Hebei province,this paper first describes the requirements of pavement materials for Yanchong Expressway,and discusses the selected pavement design methods.Secondly,the gradation range of the skeleton dense structure of AC-20 C asphalt mixture was studied.According to the asphalt mixture mix design process,the Superpave method was selected and the void rate of 4% was taken as the design target when study the mix ratio of asphalt mixture.Based on the local meteorological conditions and traffic levels,an optimal skeleton compactness curve and a mix ratio of asphalt mixture with high pavement performances were obtained,by selecting raw materials,studying the saturation of asphalt mixture and the voids in the mineral aggregate,and testing the low temperature crack resistance performance,waterproof damage and high temperature stability performance of the mixture.At last,the physical construction was carried out according to the optimal design mix ratio using raw materials that meet process control requirements and the standard asphalt mixture pavement construction technology.The feasibility of AC-20 C production mix proportion was approved by testing and analyzing the real project and monitoring the pavement qualitydynamically.It ensures the construction quality of expressway asphalt pavement,at the same times,it improves the traffic safety,comfort and durability of expressway asphalt pavement.