Study On Shear Resistance Of Asphalt Mixture Based On Particle Shear Analysis System

With the increase of heavy-duty traffic,the rutting,traction and upheaval of asphalt pavement become more and more serious.More and more road practitioners are aware of the urgency of improving the shear resistance of asphalt mixture,and conduct in-depth research on it.As a typical granular material,the macroscopic mechanical response of asphalt mixture is the external manifestation of the contact,interface friction and sliding behavior between the mineral materials at the micro observation level.An effective test method for evaluating intergranular shear of mineral materials is of practical significance for improving road performance and service life of asphalt mixture.This study summarized the test methods for evaluating the shear properties of asphalt mixture at home and abroad,and proposed a test method for the shear performance of asphalt mixture based on particle interface shear and the corresponding test device,and carried out the uniaxial penetration verification test.The following main conclusions are obtained:(1)The theoretical analysis results of particle mechanics show that the macroscopic mechanical properties of asphalt mixture,as a typical three-phase system,are limited by the distribution characteristics of internal particles and the properties of asphalt slurry.The derived mechanical model of particulate matter is suitable for the calculation of shear modulus of asphalt mixture obtained by this test method.(2)The high temperature stability test results show that the three design gradations(AC-13,SMA-13,OGFC-13)all meet the requirements of the specification.Based onunconfined compressive strength test of three kinds of asphalt mixture’s shear parameter cohesive force c and internal friction Angle ?.(3)Based on the control variable test method,the test conditions and procedures of the shear analysis system for asphalt mixture particles are obtained: Normal load of 100 N,shear distance of 5mm,test temperature of 60 and shear speed of 0.02mm/s.(4)The asphalt mixture with different gradations(AC-13,SMA-13,OGFC-13)and different materials(granite,glass beads,iron beads)were tested by uniaxial penetration test and compared with the results of the particle interface shear test.The test results showed a good linear correlation between the shear modulus based on the particle interface and the measured shear modulus,indicating that the particle interface shear test method is feasible.