Numerical Simulation Analysis Of Asphalt Pavement Rutting Based On Creep Test

At present, about95%of expressways in China are asphalt pavements, in whichrutting damage is one of the primary damages. The traditional researches focused ondesign and evaluation of anti-rutting asphalt mixture and structural combination ofasphalt pavement. However, constitutive models which could reflect the entire ruttingdevelopment is seldom researched, which in turn results in a poor effect of ruttingprediction. As a result, based on the summarization of current viscoelastic models,through the secondary development of UMAT subroutine within the framework ofABAQUS software, the numerical simulation analysis of rutting deformation of asphaltpavement with several viscoelastic constitutive models was carried ou. Primary researchcontents are as the following:At first, basic viscoelastic models were introduced, followed by the discussion ofsimulation effect of different models on creep deformation of asphalt mixture. Then,based on the secondary development of UMAT subroutine within the framework ofABAQUS software, subroutine codes for Burgers Model, Modified Burgers Model,Six-Parameter Model and Seven-Parameter Model were composed. CoMParing thevertical strain and creep curve of simple cylindrical model among theoretical solution,measured solution and finite element simulation results, the accuracy of developedUMAT subroutine is verified.Secondly, viscoelastic parameters of typical asphalt mixtures were obtained byuniaxial compression creep test in laboratory, in which non-linear fitting using Originsoftware was used. The viscoelastic parameters database were built, including Burgers,D-P, Modified Burgers, Six-Parameter and Seven-Parameter model. In addition, thelimitations, advantages and problems needed to be considered were discussed here also.Thirdly, rutting numerical simulation of typical asphalt pavements wereperformed based on UMAT subroutine development. Equivalent conversion principal ofvehicles loading was established. Aslo, the influence rules of different loadingamplitudes, loading time, boundary conditions and pavement structures on the ruttingdeformation was analyzed. At the same time, the effect of different asphalt layer andmaterial was discussed also.Finally, using structural rutting testing in lab, the rutting prediction was verifiedpreliminarily. The numerical rutting prediction and lab testing results at45℃werecoMPared and analyzed. The feasilibility of rutting prediction proposed in this paperwas verified in the end.