Acoustic durability of noise reducing dense or semi-dense asphalt surface layers
Original Language Title: Akustische Dauerhaftigkeit lärmmindernder dichter oder semi-dichter Asphaltdeckschichten
Low-noise road surfaces are important means for traffic noise abatement measures. Due to the diverse requirements in the surface layer (skid resistance, durability, construction and maintenance costs, etc.), dense and semi-dense noise-reducing asphaltic road surfaces are built in the major road network. While these road surfaces feature a good tyre/road noise reducing performance at the beginning of their life-cycle, these positive aspects degrade with increasing age of the road surface. Causes for this decrease of the acoustic properties are mainly assumed in alterations of the road surface texture due to heavy traffic loads.
The project ADURA aims at finding and analysing the modes of action which lead to the acoustic degradation of the dense and semi-dense asphaltic road surfaces on a scientific basis. Therefore, extensive coupled tyre/road noise and road surface texture measurements will be performed, and the acoustically relevant alterations will be identified. Based on this data, the acoustic ageing processes will be modelled. With this, assumptions will be made which road surface parameters are responsible for constant noise-reducing properties and therefore need to be preserved over the lifetime. Via systematically manufactured asphaltic specimens, means to produce acoustically stable road surface types shall be examined. These test specimens will be artificially aged under laboratory conditions and their surface properties analysed. By this, and based on the developed models, the effectiveness of the set measures will be examined. Finally, the found road surface variations will be evaluated with regard to their economic feasibility. For this, life-cycle assessments and a cost-benefit analysis will be performed.