A Numerical Method Of Predicting The Elastic Mudulus Of Asphalt Concrte

Asphalt concrete with air voids is characteristic of multi-scale and multi-phase and the elastic modulus is one of the most important parameters for the design of pavement materials.Asphalt concrete is usually modeled as a four-phase composite material,composed of asphalt mortar,air voids,coarse aggregates,and interfacial transition zone and the elastic modulus of asphalt concrete can be obtained through numerical methods or micromechanics theory.In this paper,the mesostructure of asphalt concrete with polygonal aggregates is reconstructed through computer simulation.Combined with the fast Fourier transform method,a multi-step method is developed for predicting the elastic modulus of asphalt concrete.The quantitative relationship between the elastic modulus of asphalt concrete and the mechanical properties and volume fraction of each component phase is analysed,which provides a theoretical basis for the optimization design of asphalt pavement materials.First,polygonal aggregates are generated and distributed in a square simulation element.The periodic boundary conditions are introduced to eliminate any wall effects.A multi-step method is then developed for predicting the elastic modulus of asphalt concrete.With the fast Fourier transform method and micromechanics theory,the elastic moduli of rubber asphalt concrete,asphalt concrete with air voids,and conductive asphalt concrete are obtained.Through comparison with the experimental results obtained from the literature,it is confirmed that the numerical method is of higher accuracy.Finally,based on the numerical results,the main factors that affect the elastic modulus of asphalt concrete with air voids and conductive asphalt concrete are analyzed quantitatively.