The Virtual Experimental Study Of Asphalt Mixture Mechanical Properties Based On DEM

The service life of asphalt surface is determined by mechanics performance of asphalt mixture,a kind of multi-phase composite material,and asphalt mortar,coarse aggregate and void make up of it.But the indoor test can not reveal some important micromechanical properties,it is difficult effect of microstructure of analytical materials on mechanical properties of asphalt mixture.Therefore,macro mechanical parameters and internal mesoscopic structure properties are combined to establish the meso-asphalt mixture model based on the distinct element,and the influence of the fine aggregate on the mechanical properties of the asphalt mixture is briefly analyzed.Firstly,on the WDW-300 E universal testing machine,the indoor uniaxial compression test was carried out on the rock specimen,and the longitudinal stress-strain data and the elastic modulus and Poisson’s ratio of the coarse aggregate were obtained.At the same time,the asphalt mortar was subjected to uniaxial The creep test was carried out and the macroscopic parameters required for the Burgers model of the asphalt mortar were obtained by the static creep test curve.Secondly,the image feature extraction of AC-13 section image is carried out to obtain the ratio of coarse aggregate,asphalt mortar and void composed of asphalt mixture.At the same time,the structural elements are used to calculate the mathematical morphology of the image,and the characteristic information of the asphalt mixture,the proportion of particles with different particle size is calculated,which provides data for the establishment of discrete element model of asphalt mixture based on PFC.Finally,all these discrete element model with PFC developed above and the choice of calculation parameters are correct are verified by comparing with the uniaxial compression tests.Based on this model,virtual experiment simulation is operated,then effect of fine aggregate on mechanical properties of asphalt mixture is analysed in several macro-micro angle,the reasons of this phenomenon is discussed.These research results has positive significance for rich analysis method of asphalt mixture and deep understanding of material composition characteristics of asphalt mixture.