Abstract
Regarding the reduction of road vehicle noise by drainage asphalt pavement, two kinds of experimental investigations were performed. Firstly, sound propagation was observed on two types of drainage asphalt pavements and a dense asphalt pavement. In this experiment, an omnidirectional sound source was located under the body of a passenger car and a heavy truck. As a result, it was found that the excess noise reduction on drainage asphalt pavement can be attributed to the sound absorption during multiple reflection uncle': the vehicle body and this effect depends on the vehicle type. Secondly, pass-by tests were performed on the three kinds of pavements using the same test vehicles. In this experiment, tire/road noise was measured on each pavement and by comparing the results, the reduction of tire/road noise due to the porosity of drainage asphalt pavement was estimated. Based on the results of these investigations, a calculation model for the prediction of vehicle noise propagation on drainage asphalt pavement has been proposed.
