PERMEABILITY: IMPLICATIONS IN ASPHALT MIX DESIGN . HIGHWAYS SUPPLEMENT: ASPHALT 90

The requirements of paving materials are more recently being defined in terms of engineering properties rather than traditional empirical parameters. The ability of open graded mixes to drain water from beneath vehicle tyres is dependent on their permeability. The author describes the use of the falling head permeameter and discusses the implications of the results of tests using the method on three different mixes of open textured bitumen macadam. The binder content was varied in the mixes to obtain a different voids volume. An important factor in water permeability measurements is the achievement of a sound seal on the sides of the specimen. Results showed that at high binder contents, permeability is more sensitive to changes in void content than at lower binder contents. The apparatus developed can be used to estimate the rate of vertical flow through specimens under closely controlled conditions. A maximum limit of 0.003 cm per second is proposed for densely graded mixes to give good durability, and a minimum of 1 m per day should be used for open graded mixes for free drainage. For the covering abstract of the supplement see IRRD 828953.

  • Availability:
  • Corporate Authors:

    FAVERSHAM HOUSE GROUP LTD

    FAVERSHAM HOUSE, 111 ST JAMES'S ROAD
    CROYDON, SURREY  United Kingdom  CR9 2TH
  • Authors:
    • KHALID, H
  • Publication Date: 1990-1

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00604121
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Feb 28 1991 12:00AM