In Europe, 17% of the population is exposed to environmental noise levels of more than 65 dB(A), a level that can have negative health effects. To reduce the traffic noise nuisance arising from contact between the tire and the road surface, French road contractors have developed effective surfaces that can reduce the noise by several decibels. The performance of this surface coating is essentially obtained from a reduction in the particle size of the components of the surface layer and an increase in the proportion of voids in the asphalt. One French firm is now offering Epsibel, a roadbed consisting of two layers of high porosity bituminous concrete with very differing aggregate size. The lower layer consists of an HP 10/14 porous asphalt, with 2.5% of bitumen 1.5 in. thick. The upper layer, 0.75 in. thick, consists of Microphone HP 4/6 made up of 4.5% highly cohesive modified bitumen and 0.8% glass fiber. This thin layer helps reduce noise emission, while the porous structure absorbs engine noise and other vibrations. Another development to combat noise nuisance in France is Colsoft asphalt. Its granular formulation incorporates chopped rubber from scrap tires. In addition to low road noise, it has a matte appearance, which improves visibility by reducing reflections from light sources. Porous asphalts, which are effective at noise suppression but have been accused of clogging, are experiencing renewed popularity.

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  • Corporate Authors:

    Scranton Gillette Communications

    380 E Northwest Highway, Suite 200
    Des Planes, IL  United States  60016-2282
  • Publication Date: 2000-5


  • English

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Filing Info

  • Accession Number: 00795623
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 10 2000 12:00AM