Research On The Creep Damage Properties And Constitutive Model For High Visco-elastic Asphalt Mastic

Asphalt sand mixture is a typical thermal visco-elastic materials,with typical visco-elastic properties,show the deformation mechanical behavior of temperature and time obviously.Therefore,the visco-elastic properties of asphalt sand was focused the attention of scholar.Burgers model can describe the rheological behavior of asphalt sand,and as isotropic material,using the continuum theory to describe the mechanical properties.When asphalt sand molding,however,there are some cracks and micro defects,describe the visco-elastic behavior of asphalt sand from the microscopic creep,rain boundary on the micro hole forming micro defects to the macro crack,until failure destruction.Only we coupling the creep and damage can we describe the creep failure,for Burgers model has the consolidation effect,and can't describe the state of creep damage.According to the above,this paper in order to better characterize the creep damage behavior.The main content of the research are as follows:1 In theory,deduces visco-elastic creep damage constitutive model of asphalt sand.The Kachanov damage variable coupling to Burgers formed a more reasonable creep damage constitutive model;2 Experiments:consider the previous related with stress absorb layers,according to the existing modified asphalt,aggregate,in accordance with the specification requirements,we study the high visco-elastic asphalt sand mixture,and the creep test under different temperature,provides the basis for study of the visco-elastic property of asphalt sand.3 Numerical calculations,the asphalt sand visco-elastic parameters,was obtained by creep test.The creep process of asphalt sand under different temperature are numerically simulated by the finite element software ABAQUS,the results show that the finite element analysis of the related curve index curve and the experiment results,and the creep of the first two stages,has better correlation.Through the above study get the following conclusions:1 In this paper,we study the municipal road in stress absorbing layer of asphalt sand mixture graduation,determine the grading for creep test;2 Creep test was used for numerical simulation of the visco-elastic parameters for creep damage analysis,numerical simulation shows the first two stages have better reflection,but due to the finite element software doesn't have the failure criterion and need modify the constitutive model,which provides the theoretical basis to describe the creep damage of asphalt sand numerical simulation.3 By coupling the damage actor to the Burgers model and the coupling damage creep model,has the better reaction process of creep damage when compared with Burgers model and creep tests.The innovation points of this paper:1 Put forward the municipal road stress absorbed layer material,high visco-elastic asphalt sand mixture graduation.2 Through asphalt sand creep test got high visco-elastic model parameters,provides the basis for numerical simulation parameters.3 Creep damage model can better describe the creep properties of asphalt sand than Burgers model,provides reference model for numerical simulation of creep damage.