Study On The Influence Of Recycler Based On Molecular Simulation On The Performance Of Hot-Recycled Asphalt Mixture

The regeneration effect of asphalt regeneration technology depends on the diffusion behavior of regenerated agent and the miscibility process of new and old asphalt.Therefore,based on the asphalt molecular model of molecular dynamics theory,this thesis studies the diffusion of regenerated agent at different temperatures.Through experimental means and Combined with theoretical analysis,the influence of different regenerant content on the pavement performance of recycled asphalt mixture was analyzed.The main results are as follows:(1)Construct the matrix asphalt molecular model based on the principle of average molecular model,characterize asphalt aging by adding functional groups on the basis of matrix asphalt,and select three representative light oils,waste oils and chain regenerants for simulation,construct the molecular model of the regenerant,select the appropriate calculation parameters such as force field parameters,potential energy functions,and boundary conditions during the simulation process,and verify the density,surface free energy,and cohesive energy density and solubility parameters of the constructed model from a thermodynamic point of view,The calculation results show that the constructed model can better characterize the performance characteristics of asphalt and regenerant,and provide a basis for subsequent calculations.(2)The recycled asphalt mixing model and the new and old asphalt double-layer model were constructed,the mutual diffusion between the new and old asphalt and the recycler was simulated from the microscopic perspective,the mean square shift and diffusion coefficient were introduced to quantitatively describe the molecular migration law,and the influence of different regenerators on the miscibility of new and old asphalt was analyzed;By calculating the changes of various parameters at different temperatures,analyzing the influence of temperature on diffusion,analyzing the density and relative concentration of the two-layer model from the perspective of thermodynamic energy exchange,van der Waals potential energy and electric potential energy were introduced to explore the miscible process of old and new asphalt.The simulation results show that the diffusion process is mutual,and van der Waals force is the main driving force of the diffusion process,in addition,molecular thermal motion is also an important factor affecting diffusion.Under the same conditions,the diffusion miscibility effect of light oil and waste oil regenerator on new and old asphalt is better than that of chain recycler.(3)The old asphalt and old aggregate were obtained by extracting and separating the RAP material through indoor test,and the recycled asphalt was obtained by adding different amounts of recycler,and the performance of the recycled asphalt was tested,and the light oil regenerator was preferred.After mixing RAP and recycler,new asphalt and new aggregate were added for Marshall test to determine the best oil-stone ratio,asphalt mixture with different regeneration efficiency was obtained by changing the amount of recycler,and road performance test was carried out,and finally the relationship between the regenerator content and the properties of the recycled asphalt mixture was analyzed based on the grayscale correlation theory,and the optimal content of light oil regenerator was determined to be 8%.(4)Combined with engineering examples and laboratory test research,use thermal regeneration technology to construct and verify the test road,strictly control the quality indicators,and explore the construction technology and regeneration effect of plantmixed thermal regeneration treatment on asphalt pavement diseases,in order to provide a basis for the improvement of asphalt pavement.Maintenance and improvement provide scientific basis and technical support.