Analysis On Influence Of Mechanical Strength Between Base Course And Surface Course To The Asphalt Pavement Performance

With the rapid development of transportation construction，asphalt pavement hasbecome the main pavement of high-grade highway in China. The asphalt pavement isassumed to be a continuous multi-layer elastomer structure during the design process inthe current design specification. However，the interlayers are actually not continuousbut frictional contacted with each other. Bonding states between each layer have greatinfluence on the stress capacity of asphalt pavement structure，and different stresscapacities will affect the pavement performance. Therefore, it is essential to study thecontact status of asphalt pavement layers.Materials used in base-course and surface have great difference and the contactissues are more obvious， so this essay focused on the contact issues betweenbase-course and surface. Cement-stabilized gravel asphalt pavement is regarded as theresearch object in this essay，and the research is carried out in the following aspects.Firstly，analyze the mechanical strength between base-course and surface ofsemi-rigid base asphalt pavement through BISAR software，and study the influence ofbase-course and surface materials to interlayer stress. The change regulation of shearstress, normal stress variation with base modulus, base thickness, modulus of thesurface layer, the surface layer thickness, vertical load, and horizontal load is reached.Secondly，take Electronic Tensile Testing Machine as the platform and useself-made fixture to make base-surface shear test，and then research the different affectsby different test conditions. The relationship of base-surface interlayer temperature，loading speed and shearing strength are built; temperature and loading speed will bothaffect the interlayer shearing distinctly，especially the temperature.Thirdly，the influence on pavement structure rutting by the strength of base course，lower seal coat types and dosage of priming oil are analyzed through high temperaturerutting and immersion rutting test and orthogonal test method. The result shows thebasic strength is the most influential aspect，and secondary influential aspect is loverseal coat types and then the dosage of priming oil is the least influential one.Fourthly，use ABAQUS to build a three-dimensional pavement model and toanalog compute the stress capacity under different base-surface interlayer contact status.The change regulation of surface flexure，horizontal tensile stress，vertical tensilestress，vertical shearing strength，longitudinal shearing strength and horizontal shearing strength are reached. All the results show significant meanings on analyzing therelationship of surface damage and contact status of base-surface interlayer.This paper was sponsored by the civil engineering materials engineering laboratoryof national local traffic opening Fund project “Research on the relationship between theinterfacial configuration, microscopic damage mechanics and fatigue damage in asphaltpavement structure.”...