Improving Strength and Creep of Reclaimed Asphalt Pavement Base Course Blends with Combinations of Chemical Stabilizers

In situ recycling of Reclaimed Asphalt Pavement (RAP) in highway base course can provide both environmental and economic benefits for applications such as widening, shoulder addition or Full Depth Reclamation (FDR). RAP is a well-drained granular material, however 100% RAP has low bearing strength and creeps under load. The objective of this research was to improve RAP’s strength while reducing creep to an acceptable level through blending with crushed limestone aggregate and/or by chemical stabilization. Blends of 50%/50% and 25%/75% RAP/limerock were tested with combinations of asphalt emulsion and Portland cement at concentrations from 0% to 2%. Blends were compacted, cured, and tested for strength and deformation by the California Bearing Ratio (CBR) and modified Marshall tests. Specimens were tested dry and soaked to evaluate retained strength. One-dimensional seven-day oedometer creep tests were performed to evaluate long term deformation. RAP/aggregate blends have the potential for successful use as base course material. RAP blends with 50% limerock base plus various combinations of asphalt emulsion and Portland cement stabilizer attained acceptable CBR strength and creep. RAP blends with 75% limerock attained marginally acceptable CBR and low levels of creep without any chemical stabilizer. A strong positive correlation was observed between CBR and Marshall stability and a weak positive correlation was observed between creep and Marshall flow. Significant variability was noted between results with different blends and stabilizing agents. Performance testing should be conducted to establish the suitability of a specific RAP/aggregate/stabilizer blend.

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• Supplemental Notes:
  • This paper was sponsored by TRB committee AFP70 Mineral Aggregates.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Bleakley, Albert M
  • Cosentino, Paul J
  • Othman, Blnd
• Conference:
  • Transportation Research Board 94th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2015-1-11 to 2015-1-15
• Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: 18p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Asphalt emulsions; Base course (Pavements); California bearing ratio; Creep properties; Deformation; Limestone aggregates; Marshall test; Portland cement; Reclaimed asphalt pavements
• Subject Areas: Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I30: Materials;

Filing Info

• Accession Number: 01551354
• Record Type: Publication
• Report/Paper Numbers: 15-1876
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Jan 27 2015 11:23AM