Research on Sustainable Pavements: Changes in In-Place Properties of Recycled Layers Due to Temperature and Moisture Variations

The use of recycled pavement layers in highway rehabilitation is becoming increasingly popular; however, the in-place properties of recycled materials can be significantly different from those of traditional unbound granular materials, and can differentially change with variations in temperature and moisture conditions. To effectively design pavements using recycled materials, a better understanding of their in-place properties is needed. The objectives of the study reported in this paper were to determine the in-place properties of recycled materials common to the New England region and to evaluate the changes in these properties with changes in temperature and moisture. Five instrumented pavement sections with base layers containing recycled materials were evaluated over the course of the study. Falling weight deflectometer (FWD) testing was conducted throughout the year and at frequent intervals during the spring to capture thaw weakening and recovery behavior of the materials. Modulus values for the layers were initially backcalculated from the FWD data using the BAKFAA software program, and were further refined using a forward calculation procedure. The final recommended values for the sites evaluated in this study are presented. Results of this study show that the in-place modulus values of base layers containing recycled materials can vary significantly depending upon the material type and the recycling method. The results also show that materials that are classified similarly can have very different modulus values. Furthermore, the relative sensitivity of the different materials to changes in temperature and moisture also varied. The results of this study provide useful information regarding the behavior of base layers containing recycled materials common to the New England region, and the response of those materials during spring thaw weakening and recovery periods. The reported values can be used to conduct Monte Carlo analysis to conduct a probabilistic evaluation of the designed sections, and develop confidence limits regarding the change in structural strength over different seasons.

Language

  • English

Media Info

  • Media Type: Web
  • Features: Figures; References; Tables;
  • Pagination: pp 69-78
  • Monograph Title: Airfield and Highway Pavements 2017: Pavement Innovation and Sustainability

Subject/Index Terms

Filing Info

  • Accession Number: 01687703
  • Record Type: Publication
  • ISBN: 9780784480946
  • Files: TRIS, ASCE
  • Created Date: Oct 4 2018 4:34PM