IN-DEPTH STUDY OF COLD IN-PLACE RECYCLED PAVEMENT PERFORMANCE. INTERIM REPORT

Oregon has developed a mix design procedure for cold in-place recycled (CIR) asphalt concrete pavements. The procedure involves estimation of an initial emulsion content based on gradation of recycled asphalt pavement (RAP), asphalt content of RAP, and penetration and viscosity of recovered asphalt. When an estimated emulsion content is determined, Marshall-sized specimens are prepared for a range of emulsion contents with the range centered on the estimated emulsion content. Hveem and Marshall stability, resilient modulus, and index of retained modulus (IRM) tests are performed on the specimens and a design emulsion content is selected based upon these results. Because of variations in RAP properties, continual need for field adjustments, and the difficulty of interpreting mix property test results, only the estimation part of this procedure is currently implemented. This paper describes the mix design procedure and presents lab results demonstrating the difficulty of choosing emulsion content based on Hveem and Marshall stability, resilient modulus and IRM. Data comparing design emulsion content with actual emulsion contents used in the field are presented. Selection of water content is discussed. Test results of mix properties monitored over time are presented, demonstrating the curing of the emulsion. Performance data for CIR pavements constructed from 1984 through 1988 are presented as well as initial results of an attempt to use lime during recycling to correct a stripped pavement. Significant findings as a result of this study include the following: 1) Field performance of CIR has been good, with a few exceptions. Proper project selection is extremely important. 2) Estimation procedures for determining emulsion content serve as a good starting point for field operations. Continual monitoring and adjustment of emulsion content is required in the field. 3) It is difficult to relate Hveem and Marshall stability, resilient modulus, fatigue and IRM laboratory testing to field construction conditions for CIR. 4) Mix property test results indicate that the stiffness and fatigue properties of recycled mixtures increase over a period of years. 5) Addition of 1% and 2% lime to RAP from badly stripped pavement produced better IRM results than the RAP without lime.

• Corporate Authors:

  Oregon State University, Corvallis

  Department of Civil Engineering, Apperson Hall
  Corvallis, OR  United States  97331-2302

  Oregon Department of Transportation

  140 Transportation Building
  Salem, OR  United States  97310

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Scholz, T V
  • Hicks, R G
  • Rogge, D F
• Publication Date: 1990-4

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: 60 p.

Subject/Index Terms

• TRT Terms: Asphalt concrete; Calcium oxide; Cold in-place recycling; Cold weather; Emulsions; Laboratory tests; Mechanical fatigue; Mechanical stability; Mix design; Modulus of resilience; Moisture content; Pavement performance; Pavement stripping; Performance; Recycling; Stiffness
• Uncontrolled Terms: Field performance
• Old TRIS Terms: Test results
• Subject Areas: Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00601499
• Record Type: Publication
• Report/Paper Numbers: TRR 90-2
• Contract Numbers: 5279
• Files: TRIS, USDOT, STATEDOT
• Created Date: Nov 30 1990 12:00AM