Study On Damping And Noise Reduction Performance Of Rubber Asphalt By Temperature And Rubber Powder Content

Waste tires are internationally recognized hazardous waste,China is a big country for waste tires,Inner Mongolia frequently transports coal vehicles resulting in higher waste tires than other provinces.Processing waste tires into rubber granules(powder)and incorporating them into asphalt pavement can reduce tyre/road noise.However,rubber and bitumen are temperature-sensitive viscoelastic materials,and their damping properties are significantly affected by temperature.Combined with the unique climatic characteristics of Inner Mongolia Autonomous Region,this paper studies the vibration and noise reduction performance of rubber asphalt at different temperatures and different dosages.It provides a theoretical basis for low-noise road construction in Inner Mongolia Autonomous Region.The results of the study are as follows:(1)In this thesis,the noise reduction performance of rubber asphalt was evaluated by complex shear modulus,complex viscosity and phase angle,and the influence of the incorporation amount on the damping performance of rubber asphalt under high temperature conditions was studied.It was found that with the increase of the amount of admixation,the complex shear modulus and rutting factor increased significantly,the phase angle decreased significantly,the elastic composition of bitumen increased,and the ability of bitumen to consume vibration energy was improved.Under different temperature conditions,the changes of storage modulus,loss modulus and complex viscosity of rubber asphalt with shear frequency were analyzed and it was found that the incorporation of rubber powder could greatly improve the crosslinking degree of rubber asphalt itself,improve the internal consumption of damping,and improve its vibration absorption and damping ability.When the amount of rubber powder content reaches more than 18%,rubber asphalt has better damping performance.(2)It can be obtained by multiple stress creep test(MSCR): under the same stress level,with the increase of rubber powder admixment,the deformation recovery ability of asphalt is continuously enhanced,and the non-recoverable creep flexibility is continuously reduced.This reflects that rubber powder can improve the recovery capacity of asphalt,that is,the bitumen can better lose and store the vibration energy after being stressed,and improve the vibration and noise reduction performance of asphalt.(3)The viscoelastic continuous damage theory(VECD)model was used to study the fatigue resistance of rubber asphalt.With the continuous increase of rubber powder incorporation,the deformation resistance of bitumen continues to increase,and its complex shear modulus also increases.However,there is a certain threshold for the amount of inclusion,and the study shows that the optimal dosage of rubber powder should not exceed24%.(4)The damping performance,natural frequency and transmission ratio of different amounts of rubber bitumen under low temperature conditions were found to show that the damping performance of rubber asphalt increased with the increase of the proportion of rubber powder at the same temperature.With the decrease of temperature,the larger the proportion of rubber powder incorporated,the lower the glass transition temperature of rubber asphalt,and the better the damping effect.(5)Using time-frequency domain analysis,it is found that the incorporation of rubber powder can make asphalt have a greater degree of vibration level attenuation.By comparing the sound level curves and amplitude-frequency curves of rubber asphalt with different dosages under different temperature conditions,it can be concluded that rubber powder can effectively reduce the glass transition temperature of asphalt,broaden the road temperature range of asphalt in low temperature climate,and have the most significant noise absorption effect in the 100～200Hz frequency band.