Simulation of meso factors influencing fracture performance of dense-graded asphalt concrete at low temperature  

细观因素对密级配沥青混合料低温断裂试验的影响仿真模拟研究（英文）

作　　者：Zhang Yao Huang Xiaoming Ma Tao Zhang Deyu 

机构地区：[1]School of Transportation, Southeast University, Nanjing 210096, China [2]School of Architecture Engineering, Nanjing Institute of Technology, Nanjing 211167, China

出　　处：《Journal of Southeast University(English Edition)》2017年第3期293-300,共8页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of China(No.51378006,51378121)

摘　　要：In order to characterize the impacts of key factors on the low-temperature fracture performance of dense-graded asphalt concrete, the virtual bending fracture test is simulated by using the discrete element method( DEM) and emulation software PFC3D( particle flowcode in three-dimension). A virtual specimen generation procedure consisting of aggregate gradation, irregular clumps, asphalt mortar and air void content is performed based on the random generation algorithm and irregular coarse aggregates library. Then, the virtual fracture test is conducted after adding the micro mechanical contact models to the specimen, and the validity of virtual modeling is verified by the comparison of simulation test data and lab test data. Additionally, an orthogonal test is designed to investigate the impacts of the volume fraction of coarse aggregates and air voids, stiffness of coarse aggregates and asphalt mortar, internal bond strength of asphalt mortar and distribution of coarse aggregates and air voids on low-temperature fracture performance based on virtual simulation.The results showthat all the factors have effects on fracture performance to various degrees, while the value of the bond strength of asphalt mortar is found to be the most important determinant of tensile strength and strain-energy density. The volume fraction of coarse aggregates is considered to be the most important determinant of tensile strain. Therefore, to obtain a high low-temperature fracture performance of densegraded asphalt concrete, it is important to consider the microstructure and properties of asphalt mortar and aggregates.In order to characterize the impacts of key factors onthe low-temperature fracture performance of dense-gradedasphalt concrete, the virtual bending fracture test is simulatedby using the discrete dement method （DEM） and emulationsoftware PFC3D （particle flow code in three-dimension）. Avirtual specimen generation procedure consisting of aggregategradation, irregular clumps, asphalt mortar and air voidcontent is performed based on the random generation algorithmand irregular coarse aggregates library. Then, the virtualfracture test is conducted after adding the micro mechanicalcontact models to the specimen, and the validity of virtualmodeling is verified by the comparison of simulation test dataand lab test data. Additionally, an orthogonal test is designedto investigate the impacts of the volume fraction of coarseaggregates and air voids, stiffness of coarse aggregates andasphait mortar, internal bond strength of asphalt mortar anddistribution of coarse aggregates and air voids on low-temperature fracture performance based on virtual simulation.The results show that all the factors have effects on fractureperformance to various degrees, while the value of the bondstrength of asphalt mortar is found to be the most importantdeterminant of tensile strength and strain-energy density. Thevolume fraction of coarse aggregates is considered to be themost important determinant of tensile strain. Therefore, toobtain a high low-temperature fracture performance of dense-graded asphalt concrete, it is important to consider themicrostructure and properties of asphalt mortar and aggregates.

关 键 词：ASPHALT mixture FRACTURE property LOWTEMPERATURE virtual test PFC3D influence FACTORS 

分 类 号：N0[自然科学总论—科学技术哲学]