The acoustical character of low noise asphalt pavement was studied theoretically and experimentally. Its normal incident absorption coefficient can reach 0.5 - 0.7, much better than that of general asphalt pavement, ...The acoustical character of low noise asphalt pavement was studied theoretically and experimentally. Its normal incident absorption coefficient can reach 0.5 - 0.7, much better than that of general asphalt pavement, although both are the same in thickness and maximum aggregate size. The connected porosity is the most major parameter, which can control the coefficient. The more the porosity is, the higher the coefficient is. The peak value of normal incident absorption coefficient will increase and move towards lower frequency when the depth of pavement is thickened. The peak will approach a stable value when the depth is about 40 mm. The measurement results show that the traffic noise can reduce 4 dB - 8 dB at a test low noise asphalt pavement when a car speed is more than 60 km·h-1展开更多
文摘The acoustical character of low noise asphalt pavement was studied theoretically and experimentally. Its normal incident absorption coefficient can reach 0.5 - 0.7, much better than that of general asphalt pavement, although both are the same in thickness and maximum aggregate size. The connected porosity is the most major parameter, which can control the coefficient. The more the porosity is, the higher the coefficient is. The peak value of normal incident absorption coefficient will increase and move towards lower frequency when the depth of pavement is thickened. The peak will approach a stable value when the depth is about 40 mm. The measurement results show that the traffic noise can reduce 4 dB - 8 dB at a test low noise asphalt pavement when a car speed is more than 60 km·h-1
