Effect Analysis Of Temperature On Damping And Noise Reduction Of Rubber Granular Asphalt Mixture

Waste rubber tires and traffic noise become an important source of traffic environmental pollution,reasonable pavement structure and suitable pavement material selection can effectively reduce the noise,and the use of rubber particles made of waste tires into asphalt mixture,not only play a role in reducing noise,but also reduce the pollution of waste tires,play a role in waste utilization.In this thesis,through accelerated loading tests at different temperatures,the axial strain was analyzed from a macro perspective and the damping performance of rubber particle mixture was explained.Then,from a micro perspective,the rubber model,the three-component asphalt model and the ore model with silica and aluminum oxide as mineral components were constructed by molecular dynamics software.The asphalt-mineral model and rubber-asphalt-mineral model were established.On this basis,dynamic simulation and mechanical property analysis at different temperatures were carried out,and macro damping noise reduction mechanism was explained from the perspective of molecules,and the following research results were obtained:(1)Accelerated loading test was carried out from a macro perspective to analyze the influence of temperature on damping performance of rubber pellet asphalt mixture in the low temperature range of 0℃-20℃.The results showed that: The dynamic modulus of rubber asphalt mixture is smaller,so the damping performance is better than that of ordinary asphalt mixture.With the decrease of temperature,the strain level of rubber asphalt mixture is higher than that of ordinary asphalt mixture specimen,and the decrease of temperature also has relatively good damping performance for rubber asphalt mixture.Compared with20℃,the dynamic modulus of rubber pellet asphalt mixture is about 3 times higher than 0℃,so the damping performance decreases with the decrease of temperature.From the perspective of energy analysis,the kinetic energy of rubber granular asphalt mixture is much higher than that of ordinary asphalt mixture when the temperature is higher than 10℃,indicating that its energy dissipation is faster,indicating that its damping performance is better.When the temperature is lower than 10℃,the kinetic energy of similar materials decreases significantly,so its damping performance also decreases significantly.But the damping performance of rubber pellet asphalt mixture is slightly higher than that of ordinary asphalt mixture when the temperature is lower than 10℃.(2)Molecular dynamics software was used to study the kinetic energy and mechanical properties of rubber-asphalt-mineral at different temperatures from the microscopic point of view,and to explain the change mechanism of macro damping properties from the microscopic point of view.The results showed that: By comparing and simulating the energy changes of various models at different temperatures,it can be concluded that the kinetic energy between molecules will increase significantly after the incorporation of rubber,which effectively indicates that with the incorporation of rubber,more kinetic energy is used to dissipate the loading energy,and the energy dissipation caused by the increase of kinetic energy is released in the form of heat energy.Therefore,the incorporation of rubber improves the corresponding damping performance.With the decrease of temperature,kinetic energy decreases gradually,and damping performance decreases correspondingly.Because the kinetic energy of mixed rubber is always higher than that of unmixed rubber at the same temperature,the damping performance of rubber granule asphalt mixture is higher than that of ordinary asphalt mixture at the same temperature.The mechanical properties of asphaltmineral and rubber-asphalt-mineral models are analyzed.As the volume modulus,shear modulus and Young’s modulus of rubber are reduced,the elastic modulus of rubber decreases,indicating that rubber is more prone to elastic deformation,and more energy can be consumed in the process of elastic deformation,so its damping performance is better.