Abstract

Road surface should be constructed in a way that ensures safe and comfortable traffic conditions, not only when it is newly paved but also during its entire lifetime. An important factor in the asphalt mixture design process is also the expected pavement durability and stability of pavement properties over time. In many countries, road surface starts to play a significant role in traffic noise reduction actions. Selecting a particular mixture type for pavement, its mechanical and acoustical durability should be properly balanced. Road surface ageing is a widely studied phenomena from the mechanical point of view (cracking, rutting, etc.), however change of its noise characteristics over time is less investigated. The pavement ageing influence on tyre/road noise presented in this paper was derived based on numerous CPX measurements performed on 26 road sections located in Europe. Detailed analysis taking into account the overall CPXI values, as well as separate indexes calculated for passenger cars and heavy trucks, was conducted for six different types of bituminous wearing courses with maximum aggregate size of 8, 11 and 16 mm. Pavements were listed in two groups: normal noise (dense asphalt concrete, stone mastic asphalt, thin asphalt layer) and reduced noise (porous asphalt concrete, double layer porous asphalt concrete, asphalt rubber). For the vast majority of sections the noise measurements were made several times over a period of a few years, usually starting one month after pavement construction. Concluding, for dense road surfaces the noise emission increases by 1-2 dB over the first 1-2 years and then stabilizes, sometimes slightly decreases. For double layer porous asphalts a moderate increase was noted, 0.5 dB/year on average. Asphalt rubber pavements were characterized by continuous and stable increase in noise, about 1 dB per year. The obtained results confirm available literature data with an exception for single layer porous asphalts, for which the ageing effect was found to be negligible.

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