Towards the use of RAP in GB5® mix design

Aggregate packing concepts developed in the field of high-performance cement concretes, initially by Caquot (1937) then by contemporary researchers since the 1970's, were transposed to the field of asphalt concretes. These concepts, associated with the use of Polymer-modified Bitumen (PMB), enabled the development of a new generation of dense high-modulus asphalt concretes. The single or double gap-graded grading curves of these mixes, lead to a great interlock between coarse aggregates. Consequently there is no need for low penetration grade bitumen to fulfill the European EME2 specification requirements, in particular the 14,000 MPa stiffness modulus value at 15°C. In addition, Reclaimed Asphalt Pavement (RAP) is known to improve some mechanical properties of mixes when taking care to mitigate RAP bitumen properties with the virgin bitumen. In the specific case of gap-graded grading curve, such as in GB5®, introduction of continuously graded RAP leads also to specific design. Aggregates packing principles and mechanical performances measured in the lab are presented in the paper. Examples of GB5 mix designs including up to 50% of RAP are given. It is shown than High Modulus properties can still be reached with gap-graded mix including high amount of RAP. The 8-year French experience of GB5 with RAP is exemplified.

• Record URL:
  http://arrbknowledge.com
• Authors:
  • Olard, F
  • Pouget, S
• Conference:
  • AAPA International Flexible Pavements Conference, 18th, 2019, Sydney, New South Wales, Australia
• Publication Date: 2019-8

Language

• English

Media Info

• Pagination: 10p
• Monograph Title: Our everlasting roads – enabling future mobility: 18th AAPA International Flexible Pavements Conference and Exhibition, 18-21 August 2019, Sydney

Subject/Index Terms

• TRT Terms: Aggregates; Asphalt pavements; Bituminous binders; Bituminous pavements; Mix design; Performance; Waste products (Materials)
• Uncontrolled Terms: Pavement technology
• ATRI Terms: Aggregate; Asphalt; Mix design; Performance; Polymer modified binder; Reclaimed asphalt pavement
• Subject Areas: Geotechnology;

Filing Info

• Accession Number: 01718284
• Record Type: Publication
• Source Agency: ARRB Group Limited
• Files: ITRD, ATRI
• Created Date: Sep 26 2019 12:33PM