Study On Compaction Process Of Asphalt Mixture Based On Discrete Element Method

The existing research shows that the early damage of asphalt pavement in China is directly related to the degree of compaction in the construction process.The traditional compaction control technology can't predict the degree of compaction in the construction process,so insufficient compaction or over compaction is difficult to be observed in time.Researchers have been looking for a method which can predict the internal compaction state of Asphalt Pavements under different compaction parameters.Nowadays,the common numerical simulation methods include discrete element method and finite element method at the research of compaction process of asphalt mixture.Because the aggregate of asphalt mixture has various shape,large quantity and random distribution in practical engineering.The influence of the internal characteristics of the mixture on its ma cro mechanical characteristics is often neglected by the finite element method,but discrete element method(DEM)has the unique advantages in solving the problem of granular material.In this paper,DEM is selected to simulate the compaction process of asphalt mixture.In this paper,the compaction process of asphalt mixture is simulated by particle flow software PFC3 D.The coarse aggregate in the asphalt mixture which play a role of skeleton support has only been generated,and the parallel bond model is used to simulate the asphalt mortar.The influence of different rolling load type,different proportion of asphalt mortar,different gradation and different particle shape on compaction of asphalt mixture are studied.The study found that smaller aggregate particles keep close to large particles and the particle velocity increase at first and then decrease,the contact force between particles gradually increase,the porosity gradually decreases during compaction process;the thickness of asphalt mortar packaged by aggregate is more big,the porosity is lower;the content of small diameter aggregate has great influence on the porosity;the strip particles and the triangular particles is smaller,asphalt mixtures can be compacted more easily.In this paper,the compaction process of asphalt mixture is pre calculated and simulated by DEM,and compaction degree of asphalt mixture under different operation parameters is observed.It is hoped that it can provide some reference for the construction scheme and construction process of the asphalt pavement in the actual production process.