Abstract
We carried out some measurements of vehicle noise and a normal incidence absorption coefficient of the poro-elastic road surface (PERS), which was made of rubber granules obtained from wasted tires, and have obtained the following findings. We consider that PERS has a very large reduction effect on the vehicle noise. 1) PERS has very large noise reduction effects of about 16-19dB for passenger cars and about 6-10dB for heavy trucks at a speed of 40-120km/h. 2) PERS has a largenoise reduction effect in the frequency range less than 600Hz, where the drainage asphalt pavement has little reduction effect. This makes the noise reduction effect of PERS much larger than that of the drainage pavement. 3) The peak value of normal incidence absorption coefficient of PERS is about 0.9. It appears in the frequency range of 800-2, 000Hz, where the peak frequency differs from each other due to the thickness of PERS.
