The Comparison Analysis among Noise Reduction of Different Pavement Types through the Sound Absorption Measurement

In order to evaluate noise reduction effectiveness of different types of pavements, these two method, CPX method and SPB method, could usually be used in common. CPX method is based on tire rolling on the pavement surface with measuring microphones located close to a rear tire on the test vehicle. CPX method can evaluate the influence of pavement surface on traffic noise. Also SPB method is for sampling noise from traffic flows on a given pavement surface with to assessing the influence of the pavement surface on traffic noise. However these two method could be influenced by adjacent environmental conditions, for example community noise, atmospheric environment, weather condition etc. Therefor this study analysed noise reduction impacts of different types of pavement such as normal asphalt pavement, single layer low noise pavement and two-layer low noise pavement using the sound absorption measurement method. This method can measure noise levels in various frequency ranges with asphalt specimens. From the results of this study with the sound absorption measurement method, characteristics of noise levels in various types of low noise pavement and characteristics of noise levels in various frequency ranges for different types of pavement could be found.