Macro Meso Equivalent Evaluation Of Interlaminar Shear Performance Of Asphalt Pavement With Granular Base

In China,asphalt pavement structures often use granular base asphalt pavement to control the generation of reflective cracks.It can receive and weaken the concentrated stress of the paved asphalt pavement to protect the structure at that location and continue the service life of the road.Due to the loose nature of particles in the road base layer,the interlayer structure exhibits complex contact forms,usually manifested as the mutual embedding state between the protruding crushed stones in the base layer and the asphalt mixture aggregates in the surface layer.Therefore,this article proposes a model based on the mutual embedding of crushed stone aggregates between layers to simulate the composite structure of granular base asphalt pavement.It explores the influence of various influencing factors on the interlayer shear performance at the micro level,selects macro factors that are equivalent to micro factors to be converted into the estimation model,and then optimizes the replaced macro micro equivalent theoretical formula through self-designed macro experiments.A prediction model for interlayer shear performance of granular base asphalt pavement based on equivalent conversion of macro and micro factors has been developed.Provide theoretical support for the prevention of interlayer damage in asphalt pavement,and guide and correct practical applications.(1)According to the theory of composite mechanics and micro-damage mechanics,Python programming language and ABAQUS platform are used to generate particle flow model.Using ABAQUS finite element modeling and docking technology,a coupling micromechanical model of "asphalt surface-binder surface-granular base" characterized by "viscoelastic model-cohesive force model-particle flow model" under the condition of inter-layer gravel embedding is established,which lays the foundation for the micromechanical simulation analysis of inter-layer shear behavior.(2)Using the composite structure model that takes into account the intercalation of inter-layer crushed stones,systematically analyze the influence of the type and depth of the oil layer,particle size and shape,porosity,external load,temperature and other mesoscopic factors on the interlaminar shear performance,Through simulation analysis,the relationship curve between interlaminar shear stress and various factors is determined,and the interlaminar shear strength is determined using Mohr-Coulomb fracture criterion.Through multiple regression analysis,A prediction model of interlaminar shear strength of composite structures based on mesoscopic parameters is proposed.(3)In order to propose a macro-meso-equivalent interlaminar shear strength prediction model,corresponding to the meso factors,in view of the characteristics of granular materials that are difficult to form and demould,we designed a "non demoulding" composite structure test and program,corresponding to the meso factors,select the equivalent macro factors,and focus on the type and amount of interlayer bonding materials,porosity,different composition forms of surface mixture,external load,temperature,etc,The macro finite horizontal shear test is carried out to obtain the influence rule of shear strength and macro factors on interlaminar shear performance,and reveal the nonlinear test characteristics of macro interlaminar shear failure behavior.(4)The equivalent conversion relationship between macro and micro parameters is preliminarily formulated.Macroscopic factors are taken as independent variables and substituted into the above interlaminar shear strength prediction model of composite structure based on mesoscopic parameters to obtain the shear strength prediction model expressed only by macroscopic factors.The prediction model is verified and optimized by using a finite set of macro test results,and the shear strength prediction model and performance evaluation method based on macro and meso equivalence are proposed.At the same time,the purpose of accurate meso simulation prediction and macro evaluation of interlaminar shear performance is realized,which is convenient for practical engineering application.Figure [57] table [29] reference [75]...