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Traffic noise at two-layer porous asphalt : Öster Sögade, year no. 7 Kragh, Jörgen

By: Series: Technical note ; 46Publication details: Köpenhamn Road Directorate. Danish Road Institute, 2006Description: 46 sISBN:
  • 8791177979
Subject(s): Online resources: Abstract: Traffic noise has been measured at an urban road with 3 kinds of two-layer porous asphalt in Copenhagen (the Øster Søgade experiment). The measurements are part of the clogging project of the DRI-DWW noise abatement programme. The noise reduction at the thickest new two-layer porous asphalt with 2/5 mm aggregate in the top layer was between 6 and 7 dB, two weeks after the surfaces had been opened to traffic in 1999. At the remainder of test sections, the noise reduction was 5 dB when compared with a dense asphalt concrete with a maximum aggregate size of 8 mm. Measurements have been repeated every year and this technical note presents the results obtained when the pavements were seven years old. The porous asphalt voids have gradually been clogged, and after seven years the noise reduction was 1 dB at two of the test sections while the noise reduction had disappeared at the third test section. The noise level at the reference section has not increased as much as one should expect. Often an increase of 1-2 dB is experienced during the first three years or so. Had the traffic noise level at the reference surface increased more than actually measured this would have resulted in larger noise reductions just as the use of a reference pavement with larger maximum aggregate would have lead to larger noise reduction.
Item type: Reports, conferences, monographs
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Traffic noise has been measured at an urban road with 3 kinds of two-layer porous asphalt in Copenhagen (the Øster Søgade experiment). The measurements are part of the clogging project of the DRI-DWW noise abatement programme. The noise reduction at the thickest new two-layer porous asphalt with 2/5 mm aggregate in the top layer was between 6 and 7 dB, two weeks after the surfaces had been opened to traffic in 1999. At the remainder of test sections, the noise reduction was 5 dB when compared with a dense asphalt concrete with a maximum aggregate size of 8 mm. Measurements have been repeated every year and this technical note presents the results obtained when the pavements were seven years old. The porous asphalt voids have gradually been clogged, and after seven years the noise reduction was 1 dB at two of the test sections while the noise reduction had disappeared at the third test section. The noise level at the reference section has not increased as much as one should expect. Often an increase of 1-2 dB is experienced during the first three years or so. Had the traffic noise level at the reference surface increased more than actually measured this would have resulted in larger noise reductions just as the use of a reference pavement with larger maximum aggregate would have lead to larger noise reduction.