Asphalt Concrete Pavement Rutting Research Based On Discrete Element Method

With the rapid development of express way, asphalt concrete pavement which possesses smooth surface, non-seam, short construction period and other advantages gets broad application. However, during the usage period, high temperature disease of asphalt pavement becomes increasingly serious, especially rutting. Under the reciprocal action of vehicle load, rutting is the irreversible permanent deformation of asphalt pavement. W style rutting is the most common rutting style in our country, the characteristic of which is that the asphalt concrete under wheel track belt subsides after several times of vertical vehicles loads, while both sides of wheel track bulge upward. Rutting decreases the service life of highway, and does great damage to driving safety and comfort. This paper takes macro indoor test and discrete element method to make a research on rutting failure mechanism of asphalt concrete pavement from the view of materials composition and their interaction, deepened the understanding about rutting in asphalt concrete pavement.This paper analyzed the influencing factors of rutting from the structure type and strength theory of asphalt mixture. Dynamic modulus of Simple Performance Test in NCHRP project was adopted for SMA-13, AC-16and AC-20asphalt mixture in this paper. Rutting factor indicates that SMA-13has the best anti-rutting ability and that AC-16is better than AC-20. This paper also researched on compressive resilient modulus test in Specifications for Design of Highway Asphalt Pavement, the result of which is identical with dynamic modulus conclusion. Finally, Asphalt Pavement Analyzer was employed in rutting test for analyzing the influence of different frequency and load on rutting depth, which shows the relationship between rutting depth and load action times.At the same time, this paper adopted Discrete Element Method and Particle Flow Code in2Dimensions for asphalt mixture microscopic simulation. Take circle particle as aggregate and contact model on behalf of asphalt in the mixture. After simulation of uniaxial compression test, the result matches well with the stress-strain curve in laboratory test. On the other hand, the APA test simulation result also conforms to its laboratory test result. Therefore, as long as contact model and model parameters is proper, it’s feasible to take discrete element method and PFC-2D to study asphalt mixture.This paper takes Discrete Element Method to study rutting performance of asphalt mixture; the results provide theoretical basis, new ideas and reference for anti-rutting performance and Discrete Element Method research on asphalt mixture.This paper was sponsored by the National Science Foundation "Research on fatigue cracking of asphalt pavement under load coupled transient pulse seepage pressure".