UNBOUND BUT NOT UNSTUCK

This article describes the technique of placing a 30cm thick concrete roadway pavement on a 30cm thick crushed aggregate unbound roadbase, and discusses its advantages. German contractors have used this method for well over ten years, usually on motorways with heavy traffic, as an alternative to placing a 26cm thick concrete pavement on a bound roadbase. Concrete pavement was first laid over unbound roadbase in the 1930s in Germany, and some of these 60-year-old pavements are still used by traffic. This system was revived in Germany in 1979. Tests by the German Federal Road Research Laboratory and the University of Hannover on the A12 motorway have consistently shown that it is at least as good as its alternative. It has better load-bearing performance, and its unbound roadbase can use recycled aggregates made of old motorway concrete, and does not require curing. Several German standards must be applied in connection with the system, to ensure good design safety and guarantee the important properties of unbound roadbases laid under concrete pavements. The latter part of the article discusses current experience of production and placement, water permeability, modulus of elasticity, California Bearing Ratio (CBR), and on-site performance.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/14605856
• Corporate Authors:

  Palladian Publications Limited

  15 South Street
  Farnham Surrey GU97QU,   United Kingdom 
• Authors:
  • Fleischer, W
• Publication Date: 1999-4

Language

• English

Media Info

• Features: References;
• Pagination: p. 38-42
• Serial:
  • CONCRETE ENGINEERING INTERNATIONAL
  • Volume: 3
  • Issue Number: 3
  • Publisher: THE CONCRETE SOCIETY
  • ISSN: 1460-5856

Subject/Index Terms

• TRT Terms: Aggregates; Base course (Pavements); California bearing ratio; Concrete; Crushed rock; Durability; Elasticity (Mechanics); Freeways; Loads; Organizations; Pavements; Recycling; Standards; Tests
• Uncontrolled Terms: Laying
• Geographic Terms: Germany
• ITRD Terms: 4577: Aggregate; 3087: California bearing ratio; 4755: Concrete; 4173: Crushed stone; 5910: Durability; 5912: Elasticity; 8125: Germany; 3623: Laying; 5567: Load; 2752: Motorway; 9057: Organization (association); 2955: Pavement; 4573: Recycling (mater); 2961: Roadbase; 187: Specification (standard); 6255: Test
• Subject Areas: Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 00767109
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Aug 6 1999 12:00AM