The Viscoelastic Analysisof Asphalt Mixture Trabecular’s Cracking Propagation

The crack propagation behavior of asphalt pavement is one of the frontiers of thetheory and practice of asphalt pavement. Understanding of the crack expansion of asphaltmixture components and structures can help the designers and operators tocomprehensively master the development law of asphalt pavement, thereby, moreeffectively controlling measures can be adopted in the early disease of asphalt pavement.This dissertation investigated the crack propagation behavior of asphalt mixture beamsunder three-point bending based on the viscoelastic theory using numerical simulation.This dissertation firstly analyzed the study on the present situation of asphaltpavement crack expansion at home and abroad, and thus the research content was putforward. The second chapter introduced the basic theory of viscoelastic constitutiverelation for asphalt mixture material, and the finite element method and fracturemechanics basic solution for the crack propagation of asphalt mixture beams. The thirdchapter investigated the test on the fatigue fracture of asphalt mixture beams, therefore,the viscoelastic parameters and ultimate bearing capacity of asphalt mixture was obtained.The test results showed that with the increasing distance of the notch crack from themidpoint of the applied commensurate concentrated load, the crack initiation angleincreased, and the crack expanded to the load center. In the fourth chapter, theviscoelastic numerical simulation of three-point bending fatigue test was conducted.Compared with the elastic analysis results, the viscoelastic results tended to be moreaccurate and in better agreement with the test results.Based on the linear elastic theory and viscoelastic theory, this dissertation carriedout the three-point bending fatigue test of the asphalt mixture beams, and used the finiteelement method to simulate the crack propagation process of asphalt mixture beams. Theeffect of different size and different pre-sawed position on fatigue crack expansion of the beams, and the stress intensity factor and crack expansion path during the crackpropagation process were all analyzed. The results showed that the crack propagationpath were consistent with the experimental results, which suggested that the viscoelasticmodel can effectively simulate the crack propagation process of asphalt mixture beams.The research results can contribute to further clarifying the crack propagation mechanismof asphalt mixture components, and provide the theoretical basis for the prospectiveanalysis of asphalt pavement crack propagation and fatigue life prediction mechanism.