Thin Noise-Reducing Asphalt Pavements towards Sustainable Transport in Urban Areas

The objective of the research was development , optimisation , and evaluation of thin noise reducing surface layers in Germany. The mixtures were developed based on an open textured surface and stone mastic asphalt (SMA) aggregate skeleton across the whole thickness of the layer. As a result of this , they might have a slightly lower noise reducing capacity, but a greater durability compared to porous pavements, thus achieving a positive long term acoustical benefit The test pavements in Düsseldorf were subjected to continuous close proximity (CPX) method monitoring of the noise emission for more than three years of service , and showed a significant noise reduction and, unlike porous pavements, the measurements indicated a very low influence of pavement age on the acoustical performance, which indicated a stable surface texture . On the basis of the research results and past experience, recommendation on the specifications according to the relevant European standards was developed, thus contributing to the adoption of European specifications for noise reducing asphalt pavements . The research showed a high noise reduction potential of the considered thin noise reducing asphalt pavements, thus qualifying them as a good alternative for achieving a sustainable transport in urban areas through a higher level of protection against environmental noise.