Dynamic Response Of Stress Absorbed Layer On Composite Pavement And Experimental Investigations

Overlaying the asphalt mixture layer on the cement concrete pavement to form a composite pavement structure can greatly improve the driving comfort of the road surface and make up for the lack of rigid road surface.However,due to the difference in the mechanical properties of the two types of road surface,the road surface will produce reflective cracks under the effect of traffic load and temperature.Due to the entrance of atmospheric precipitation from cracks,the road surface is further damaged,and the service life of the road and pavement is seriously affected.A stress absorbing layer is added between the cement concrete and the asphalt mixture to improve the stress state of the structural layer and effectively prevent the occurrence of reflective cracks.The research content and conclusions of this paper are as followsFirst of all,using the ABAQUS software to establish the crack structure of the pavement structure,and then use the subroutine platform to impose dynamic loads on the road surface.Then,after comparing the thickness and modulus of each layer of the pavement structure layer under the action of dynamic loads,the stress and deflection of the pavement structure with directly-paved pavement structure and the stress and deflection of the directly paved road structure were studied.Improvement of Stress Concentration on Pavement,At the same time,it is concluded that changes in the thickness of the stress absorbing layer,the modulus of the stress-absorbing layer modulus,the thickness of the asphalt layer,and the soil-based modulus have a greater impact on the stress of the asphalt mixture overlay,while the cement concrete pavement thickness and cement,The modulus of the concrete pavement and the modulus of the asphalt layer have little effect on the stress of the asphalt mixture overlay structure.Second,use ABAQUS software to establish the temperature field model,and then define the external temperature subroutines that change with time on the ABAQUS subroutine platform.At the same time,the values of factors such as solar radiation,sunshine duration,air temperature,convective heat exchange,and effective road radiation are set in subroutines.A model was added to the external temperature subroutine over time to study the change in load stress under a change in temperature over a day,obtained maximum temperature stress at 16 o’clock in the afternoon.At the same time,under the condition of other factors unchanged,the stress of the pavement structure is analyzed in the pavement model,and the stress variation law of the asphalt mixture overlay layer is studied when the stress absorption layer modulus changes under the coupling stress,the change law of the obtained stress is the same as that of the dynamic load applied to the model alone..Finally,in order to verify the role of stress absorbing materials in the road,the indoor fatigue test research was conducted on the common anti-reverse materials in road anti-reverse technology,and the crack resistance of different pavement structure combinations was studied.The performance and characteristics of different anti-reflection materials were analyzed,and it was proved that anti-reverse materials can effectively improve the stress condition of the road surface and improve the fatigue life of the road surface,at the same time,it is concluded that shear stress is the main factor causing damage to composite pavements..