DENSE GRADED MACADAMS: IMPROVING COMPACTION AND PERFORMANCE

This paper describes pilot-scale studies to determine the compactibility and related performance properties of coated macadams made with a wide range of bitumen and tar contents combined with aggregates of the more important petrological types. The state of compaction was measured by using a gamma-ray core scanner to determine the void content, and comparing it with that at refusal compaction. Results showed that compaction significantly influenced the dynamic stiffness, resistance to cracking and the resistance to internal deformation. Typical compaction methods used in the UK achieved a level of compaction in the critical wheelpath zones which was 3 per cent less than the maximum in the middle of the lane. Trials showed that an improved rolling procedure and a modified method specification could increase the compaction in the wheelpaths by up to two per cent. Heavy vibrating rollers were more effective than a deadweight roller. The use of maximum laying temperatures and thickness layers also improved compaction. (TRRL)

• Supplemental Notes:
  • This paper was presented at the 4th National Asphalt Paving Conference held at the Crest Hotel, Bristol on Tuesday, 16th September 1980.
• Corporate Authors:

  INSTITUTE OF ASPHALT TECHNOLOGY

  PAPER MEWS PLACE, 290 HIGH STREET
  DORKING, SURREY  United Kingdom  RH4 1QT
• Authors:
  • Lister, N W
• Publication Date: 1980-12

Media Info

• Features: Figures; References;
• Pagination: p. 44-56
• Serial:
  • Asphalt Technology
  • Issue Number: 30
  • Publisher: INSTITUTE OF ASPHALT TECHNOLOGY

Subject/Index Terms

• TRT Terms: Aggregates; Binder content; Bitumen; Compactibility; Compaction; Conferences; Cracking; Deformation; Dense graded aggregates; Durability; Fracture mechanics; Improvements; Macadam; Measurement; Mix design; Pavement layers; Performance; Porosity; Rollers; Rolling; Stiffness; Temperature; Thickness; Vibratory equipment; Void ratios
• Uncontrolled Terms: Dense graded mixes
• Geographic Terms: United Kingdom
• Old TRIS Terms: Void; Wheel path
• ITRD Terms: 4577: Aggregate; 4929: Binder content; 4963: Bitumen; 4967: Bituminous mixture; 3686: Compaction; 5904: Compaction (state of); 8525: Conference; 5211: Cracking; 5595: Deformation; 5910: Durability; 9108: Improvement; 2952: Layer; 6136: Measurement; 4714: Mix design; 5938: Porosity; 3684: Roller; 5931: Stiffness; 6722: Temperature; 5933: Thickness; 8119: United Kingdom; 3692: Vibrating roller
• Subject Areas: Geotechnology; Highways; Materials; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00376752
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Sep 30 1983 12:00AM