Determination of Dynamic Modulus of Cold In-Place Recycling Mixture with Foamed Asphalt Using New Simple Performance Testing Equipment

A new mix design procedure for Cold In-place Recycling using foamed asphalt (CIR-foam) has been developed for Iowa Department of Transportation. Some strengths and weaknesses of the new mix design parameters were considered and modified to improve the laboratory test procedure. Based upon the critical mixture parameters identified, a new mix design procedure was developed to establish the properties of the CIR-foam mixtures. To further validate the new CIR-foam mix design procedure, dynamic moduli of CIR-foam mixtures made of seven different RAP materials collected throughout the state of Iowa were measured and their master curves were developed. The main objectives of this study are to provide 1) a standardized testing procedure for measuring the dynamic modulus of CIR-foam using new SuperPave Simple Performance Testing (SPT) equipment, 2) an analysis procedure for constructing the master curves for a wide range of RAP materials, and 3) impacts of RAP material characteristics on the dynamic modulus. Dynamic moduli were measured at three different temperatures and six different loading frequencies and they were consistent among different RAP sources. Master curves were then constructed for the CIR-foam mixtures using seven different RAP materials. The predicted dynamic modulus by a nonlinear sigmoidal model matched with the measured dynamic modulus well. Based on the observation of the constructed master curves, dynamic moduli of CIR-foam mixtures were less sensitive to the loading frequencies than HMA mixtures. It can be concluded that at high temperature, the dynamic modulus is influenced by the residual binder characteristics whereas, at low temperature, the dynamic modulus is affected by the amount of fines in the RAP materials.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Maps; Photos; References; Tables;
  • Pagination: 23p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01043824
  • Record Type: Publication
  • Report/Paper Numbers: 07-1322
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 5:55PM