A ten-week programme to rebuild part of the M5 motorway near Gloucester is drawing to a close following the first successful use of crushed blacktop materials as a capping layer beneath the new pavement. Reconstruction is limited to seven sections of the southbound carriageway, where excavations down to formation have yielded substantial quantities of broken blacktop materials for the capping layer. The 350 mm capping layer consists of 250 mm crushed blacktop topped-off with 100 mm of imported stone. Above that goes a 150 mm type one subbase, 125 mm of hot rolled asphalt, 245 mm of dense bitumen roadbase, and a 40 mm wearing course. The capping layer material, with an optimum moisture content of 5.7% and particle size 75 mm down, has proved to be a successful alternative to importing much larger quantities of stone. A variety of equipment is being used, including a Komatsu PC120 excavator equipped with a hydraulic hammer, articulated dump trucks, a Volvo L120 wheeled loader, and a Bomag BW160AD and Case Vibromax 752 compactor.

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  • Corporate Authors:

    Faversham House Group

    Faversham House, 111 St James Road
    Croydon, Surrey CR9 2TH,   England 
  • Authors:
    • Webb, C
  • Publication Date: 1989-8

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Filing Info

  • Accession Number: 00488280
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 30 1989 12:00AM