Study On Pavement Mixture Segregation Under Nature Falling Accumulation Condition

The pavement mechanical property can be adversely influenced by pavement materialuniformity. Effective and quantitative evaluation of pavement mixture uniformity has beenone of the key problems of road engineering. The pavement mixture section images wereprocessed and computed based on image processing technology.The distribution of eachgroup of aggregate was researched. Mixing homogeneity is put forward as the uniformityevaluation index. The whole cross-section of mixing evenness was each group of aggregatehomogeneity of the weighted average. The specimen homogeneity was several sectionuniformity of the weighted average.Mixture segregation phenomenon in natural falling accumulation condition easilyhappened. Using self-made funnel test units and different shape of particles in indoorsimulation test, the effects of angle of repose on the segregation degree were studied.Through self-made layered ring test device and after dyeing process of graded aggregatewhereabouts stacking test, the effect of mixture gradation on the segregation degree wasstudied. Since the actual laboratory tests, changes in material properties and grading thatrequire a lot of trial. Based on the discrete element software PFC2Dmodel to simulatedifferent friction coefficient and a variety of gradation, the discrete element method isapplied to the pavement mixture uniformity evaluation.The results show that: The more irregular particle accumulation is formed by stackingangle is bigger and the more close to the spherical particle accumulation is formed bystacking angle is smaller. In the range of maximum angle of accumulation, the greater theangle, the bigger the mixing uniformity, the smaller the degree of segregation, establishedthe accumulation Angle and degree of gradation segregation on the forecast model.According to the grading fractal theory and image calculating,Hs (AM16)＞Hs (OGFC16)＞Hs (AC16)＞Hs (SMA16). The relation was established between grading fractal dimension andthe degree of segregation. Established by discrete element PFC2Dmodel simulation laboratory tests, discrete element method simulation results are consistent with the results oflaboratory tests, which verify the feasibility and correctness of the discrete element model.