Study On Mechanical Response For HMAC Pavement Structure Based On Rigid Base

Composite pavement which adds asphalt concrete upper layer on cement concretepavement is widely used because it can concentrate structure advantages of cement concretepavement and asphalt pavement. But the damage of asphalt rut，drift and folding is becomingmore and more serious with the increase of the traffic volume and overloading vehicles，which influences the safety and comfort of the running vehicle. As a new pavement material，High Modular Asphalt Concrete(HMAC) can effectively improve the road capacity ofrutting-resistance with its advantages of high modulus，good high temperature stability andhigh shearing resistance. The general finite element software ANSYS was used in this paperto carry the numerical analysis of the mechanical response of the composite pavement onwhich HMAC applied，which provides the theoretical basis and reference for the applicationof HMAC on the composite pavement.Firstly，the3-D element model of composite pavement structure was built based on theelastic mechanics. By analyzing the characteristic of mechanical response when pavementchanged from semi-rigid base to rigid base，the proper layer of HMAC set in compositepavement is determinded. The effects to the pavement structure stress，strain，and flexure withthe various changes of the modulus of HMAC，the thickness of surfaces and axis for HMACasphalt pavement was further analyzed in this paper. Results indicate that HMAC cansignificantly reduce shear strain and inhibit the emergence of asphalt pavement rut andreasonable module scope is recommended. Secondly， on base of considering vehiclehorizontal forces，the change law of stress and strain to composite pavement which loaded bydifferent horizontal forces both in normal temperature and high temperature wasstudied.Improved effect that HMAC set in composite pavement was analyzed. Finally，basingon reasonable supposition and predigestion and viscoelastic theory，a composite pavementmodel was built to simulate the permanent deformation，and the influence of differenthorizontal forces，axle load，vehicle speed to permanent deformation of pavement wasanalyzed，and the proper layer of HMAC was recommended for the pavement suffered fromlow vehicle speed or large horizontal forces.