Drainage asphalt is defined (a porous wearing course of asphaltic concrete), comments are made on English experiments, and the problem of acquaplaning is discussed with emphasis on the Danish problem. The drainage asphalt layer introduced on some motorway stretches near Cophenhagen was 40 mm thick and was composed of 83 percent 12/18 mm crushed rock, 15 percent fines 0/2 mm and 2 percent added filler. The bitumen content is 4.1-4.3 percent, penetration 100 with addition of 0.4 percent antistripping agent of the amine type. Voids value was approximately 15 percent. In order to avoid segregation, a moderate mixing temperature of 120 deg C was used. When new, the voids should suffice to store the precipitation from a 10 minute heavy shower. The permeability will permit a day-long rain to be drained with a gradient of 20%. Observations indicate that the noise emission is less than from normal asphaltic concrete. Laboratory tests show no physical dimensional changes or any impairment of the Marshall stability when subjected to hundred freeze-thaw cycles.

Media Info

  • Pagination: p. 172-174

Subject/Index Terms

Filing Info

  • Accession Number: 00163673
  • Record Type: Publication
  • Report/Paper Numbers: S.C.W. Record 2 Proceeding
  • Files: TRIS
  • Created Date: Mar 14 1978 12:00AM