Study On Interfacial Shear Stress And Deformation Performances Of Asphalt Concrete Pavement

Deformation under periodic vehicle load directly relates to permanent deformation and fatigue crack of asphalt pavement. For semi-rigid asphalt pavement, interfacial slip is a typical damage phenomenon of road with slope or at mountains. Based on visco -elastic-plastic mechanical theory and numerical experiment, interfacial shear stress and deformation of semi-rigid asphalt pavement under vehicle load were studied in this paper.By dint of large common finite element software ABAQUS, 3D simulating analysis was done including deflection and interfacial shear stress under vehicle load at elastic state where impact of load conditions, surface modulus and thickness of surface layer on deflection and interfacial shear stress were compared; relaxation data of asphalt mixture was obtained from a creep test, then 3D simulation analysis was done including interfacial shear stress and deflection of road pavement under static load as well as semi-rectangular wave cyclical load at visco-elastic state; the creep constitutive of ABAQUS was fitted utilizing creep test data where distribution as well as evolution of permanent deformation and creep strain under long-term load with time were analyzed; the impact on deformation of road and interfacial shear stress by adding bonifibers to asphalt layers were discussed and improvement of fiber on dynamic stability and rate of deformation through rutting test was illustrated further.The vehicle's start and brake are important factors for interfacial slipping that can not be overlooked. Surface thickness has significant impact on interfacial shear stress where deflection is mainly influenced by modulus of surface layers, the incensement of surface layer's thickness can reduce interfacial shear stress between surface layer and base layer. Visco-elastic-plastic properties of asphalt mixture cause deflection, interfacial shear stress and rut varying with time, the visco-elastic properties of asphalt mixture increase interfacial shear stress between surface layer and base layer. The mechanical responses of road under semi-rectangular wave cyclical load show period changes and the fluctuating range reduced gradually with time. Enhancing the capacity of plastic deformation resistance of middle and lower surface layers where plastic deformation is mainly from during the rut develops can be effective in reducing the rut. The mechanical properties of the asphalt pavement are improved notably by adding fiber. This study has some reference meanings for design and construction of semi-rigid asphalt pavement.