Mix Design and Performance Assessment of Asphalt Concretes With Hybrid Fibers

In order to optimize the composition of the hybrid fiber,nine kinds of hybrid fibers which consisted of different proportions of lignin fiber,polyester fiber and basalt fiber were prepared according to orthogonal design method.Then the shear strength of different composite fibers modified asphalt were measured by the direct shear test and the optimum dosage and proportion of the hybrid fibers were determined through range analysis and variance analysis.At the same time the pavement performance of hybrid fiber asphalt mixture and single fiber asphalt mixture were tested and compared in laboratory.Resultsshow that the optimum dosage of hybrid fiber is 0.3%and the optimum proportion of lignin fiber,polyester fiber and basalt fiber is 1:2:2.The hybrid fiber can give full play the advantages of different single fibers so that it has a more balanced performance and has a better economy.The hybrid fiber suggested in this paper provides a new choice for the technology of pavement material modification.