Study On The Effect And Mechanism Of Traffic Noise In The Treatment Of Noise-Reducing Asphalt Pavement Material

In the process of continuous advancement of traffic,traffic noise pollution has also intensified,especially the impact of urban road noise on the lives of surrounding residents has become increasingly serious,and it is urgent to further develop noise-reducing asphalt pavement.When evaluating the noise reduction effect of noise-reducing asphalt pavement,the general attention is paid to its effect of reducing the overall sound level of driving noise.This acoustic evaluation method is relatively limited.In addition,the noise reduction effect of the existing noise reduction asphalt pavement is not directly related to the pavement material characteristics,which also limits the further development of noise-reducing asphalt pavement.Therefore,it is of great significance to study the effect and mechanism of noise-reducing asphalt pavement to reduce driving noise in specific frequency bands.First,the acoustic principle of driving noise generation and attenuation was preliminarily analyzed,and various acoustic testing methods were used to collect the driving noise of asphalt pavement in four scenarios(conventional city roads,roads equipped with sound insulation panels,tunnels,and overhead).The characteristics and rules of vehicle noise under different temperature,vehicle speed and scene conditions were analyzed.The evaluation index of road traffic noise was selected from it.It was found that in the near-field test method,the A-weighted overall sound pressure level obtained from the A-weighted 1/3 octave spectrum analysis was significantly correlated with the driving speed and the road surface temperature,which is suitable for characterizing pavement noise levels of various asphalt materialsSecondly,based on the basic principle of noise-reducing asphalt pavement to reduce driving noise,noise-reducing pavement asphalt mixtures were designed.The deformation and porosity characteristics were controlled by designing different rubber powder content and porosity schemes,their sound absorption characteristics were measured,and the formed test pieces were tested for road performance.AR-SMA-13 asphalt mixtures with a rubber powder content of 6%-18%and PAC-13 asphalt mixtures with a void ratio of 18.5%-23.6%were obtainedThen,through the indoor simulation noise reduction test,the driving noise reduction effect of the asphalt mixture test piece was measured.The influences of deformation characteristics,pore characteristics and sound absorption characteristics on the noise reduction effect of noise reduction asphalt mixture were analyzed.The noise reduction effects of various asphalt mixtures on noise in different frequency bands were obtained,and the reasons affecting the noise reduction ability were analyzed.The results show that the loss modulus,connected porosity,and sound absorption coefficient can be used as indicators of deformation characteristics,porosity characteristics,and sound absorption characteristics;the A-weighted 1/3 octave of the intermediate frequency noise has the highest overall sound pressure level,while the low frequency Noise is lowest;as the loss modulus of AR-SMA-13 increases,the noise reduction effect of intermediate frequency noise increases linearly,and there is no correlation between the noise reduction effect of low frequency noise and loss modulus;as the connected void ratio of PAC-13 increases Large,driving noise is significantly reduced overall.The improvement of the connected void ratio has a particularly significant effect on the linear reduction of low-frequency noise and high-frequency noise,and it also has a certain effect on intermediate frequency noise.Finally,through laboratory tests,it was simulated that the noise reduction ability of the noise-reducing asphalt mixture changed under rainfall and long-term use conditions.The change of the ability of each asphalt mixture to reduce the noise in the characteristic frequency band under the effect of water immersion on the surface and blockage of sedimentary soil is analyzed in detail.The results show that both the rain-covered state and the sediment-clogged state have a small effect on the noise reduction effect of AR-SMA-13 asphalt mixture,and a large effect on the noise reduction effect of PAC-13 asphalt mixture.The increase of noise in the high-frequency band is relatively obvious in the rain-covered state,and the increase in noise in the low-frequency and high-frequency bands is obvious in the blockage state of sedimentary soilAmong the driving noise in common road scenes,intermediate frequency noise dominates.In actual popularization and application,the deformation characteristics of the asphalt material have a significant effect on reducing it,and the overall sound pressure level is lower overall.Under rain and long-term use conditions,the attenuation of noise reduction is relatively light.Asphalt pavement materials have better application prospects.The research contents and conclusions of this paper can provide a theoretical basis for the subsequent development of noise reduction pavement design work,and then promote the further development of ecological noise reduction pavement materials.