Study On The Slipping And Shearing Behavior Of Asphalt Mixture Aggregate

Asphalt mixture as a typical particulate material, the macroscopic mechanicalresponse is the external manifestations of the contacting、interfacial friction and slippingbehavior between the mineral aggregate. Based on the dispersion characteristics of theasphalt mixture, the contacting、interfacial friction and slipping behavior between themineral aggregate of the asphalt mixture will be analyzed from the fine level, The strengthof the formation and failure mechanism of asphalt mixture will be interpreted, reasonablemethods and parameters of the slipping and shearing text for the mineral aggregate will beput forward, the relationship between the macroscopic mechanical behavior andmeso-structure characteristics of asphalt mixture will be established, and the design methodof asphait mixture basing on the microscopic mechanism will be put forward. The purposeof this study as these mentioned above.Firstly, discrete element model have been established using PFC2D, the microcosmicfailure mechanism of asphalt mixture have been analyzed, then the importance of contactcharacteristics of the mineral aggregate for mixture’s strength constitute have beenrecognized; The X-ray CT Scanning and Digital image processing technology were used toanalysis the contact characteristics of the mineral aggregate from the micro-level, then thequantitative evaluation index for the degree of contact of the mineral aggregate were putforward,which was marked as C1; Secondly, slipping and shearing test used to evaluate theslipping and shearing performance of asphalt mixture aggregate have been put forwardexclusively from the microscopic analysis of mixture structure, and the slipping and shearingenergy EI have been choosen as the mechanical indexes.Thirdly, based on the correlation ofslipping and shearing energy EI and rutting DS,as well as the finite element analysis, thepressure head and the sample’s size, test temperature, load mode and load rate of theslipping and shearing test have been determined; An analysis of influencing factors,including of asphalt mixture gradation, the ratio asphalt, type of asphalt, temperature andloading rate, which impact on the slipping and shearing energy EI have been carried out. In addition, because Marshall Stabilization (MS) have poor correlation with the hightemperature properties of asphalt mixture, so slipping and shearing energy EI used in placeof stability for asphalt mixture design. And through examples can obtain that the optimalratio asphalt is less than Marshall’s optimal ratio asphalt.