Reduction in Roughness Due to Asphalt Concrete Overlays Placed on Flexible Pavements

Ride quality of a pavement is important to the travelling public, and highway agencies strive to provide a smooth road network. A common strategy that is used to improve the ride quality of flexible pavements is to place an asphalt concrete overlay. In some instances, the overlay is placed on the existing asphalt concrete surface, while in other instances, a portion of the existing asphalt concrete surface is milled before placing the overlay. The reduction in roughness in terms of the International Roughness Index due to single-lift overlays placed on flexible pavements is presented in this paper using data obtained from a highway agency. The analysis considered 780 and 1,120 segments that were 0.1-mile long on non-milled and milled projects, respectively. The average IRI values for 0.1-mile long segments that was achieved for a single lift overlay on non-milled and milled pavements was 62 and 54 in./mi., respectively. The 85th percentile IRI values for 0.1-mile long segments after an overlay for non-milled and milled pavements were 77 and 66 in./mi. The percent reduction in IRI that is achieved when placing an overlay was seen to increase with increasing values of before overlay IRI. A percent reduction in IRI of over 40 percent was observed for 0.1-mile long segments having an IRI before overlay greater than 100 in./mi.


  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 436-445
  • Monograph Title: Airfield and Highway Pavements 2019: Design, Construction, Condition Evaluation, and Management of Pavements

Subject/Index Terms

Filing Info

  • Accession Number: 01718103
  • Record Type: Publication
  • ISBN: 9780784482452
  • Files: TRIS, ASCE
  • Created Date: Jul 18 2019 3:02PM