Research On Performances Of Modified Asphalt And Its Mixture For Albania Rock Asphalt(ARA)

Albania Rock Asphalt(ARA)has been paid more and more attention both at home and abroad for its advantages such as high content of asphalt,few impurities and high reserves etc.However,there is a lack of further research on ARA.For this reason,relying on the widening and upgrading project of S203 in Huarong County,Hunan Province,the performances of ARA modified asphalt and its mixture were researched by many experiments in laboratory to provide a reference for its popularization and application in the thesis.1)The basic physical and chemical properties of ARA were analyzed by laboratory tests.Three methods were applied to test the asphalt content of ARA,and all exceed 70%.The test temperature of 538℃ was recommended for the burning method.Meanwhile,the main components of mineral in ARA are silicate,calcium carbonate and calcium sulfate,as well as a small amount of metal oxides.The contents of asphaltene and colloid in the pure asphalt of ARA are higher,but the contents of saturated fraction and aromatic fraction are lower.Through the meso-analys is of ARA modified asphalt,the ARA was found to be suspended in shape and randomly distributed in asphalt mortar,and it is physical modification between the ARA and the matrix asphalt.2)The preparation method of ARA modified asphalt was determined,and the mixing amounts of ARA were preliminarily selected at 0-20%(the mass ratio of ARA to matrix asphalt).The performance test results of modified asphalt with different mixing amounts of ARA show that the ARA modified asphalt can produce a certain segregation,and its segregation degree can be reduced by heating and continuous mixing.The ARA can increase the density of modified asphalt and improve the corresponding high temperature stability,viscosity and aging resistance,and the safety can be guaranteed.3)The mixture ratio design method of ARA modified asphalt mixture was analyzed.It was determined that the asphalt and ash in A RA should be equal to replace the matrix asphalt and mineral powder in asphalt mixture during mixing,respectively.The viscosity temperature curve of ARA modified asphalt was applied to determine the mixing temperature of ARA modified asphalt mixture,and it was verified by experiments.The Marshall test results of ARA modified AC-13C show that increasing the ARA content can lead to an increase in air voids and voids in mineral aggregate,a decrease in asphalt saturation,and an increase in the optimum asphalt aggregate ratio.4)The test results of pavement performance show that the ARA can significantly improve the high temperature stability of asphalt mixture,and slightly improve the water stability.The low temperature performance is reduced to some extent,but it can meet the requirement for low temperature performance in most areas.Meanwhile,both the impermeability and the skid resistance can meet the requirements of the specifications.Considering the performances of various aspects,the suitable mixing amount of ARA is proposed at 0.5%～1.0%(the mass ratio of ARA to asphalt mixture).The results of economic analysis show that the ARA modified asphalt mixture can reduce the material costs about 38 yuan/t in comparison with SBS modified asphalt mixture.In summary,the suitable amount of ARA,the mixture ratio design method and pavement performance characteristics of its modified asphalt mixture proposed in the thesis can provide a reasonable basis for its engineering applications.