Evaluation of crumb rubber in hot mix asphalt.

Details

• Creators:
  Bennert, Thomas ; Maher, Ali ; Smith, Joseph
• Corporate Creators:
  Bayshore Recycling Corporation
• Corporate Contributors:
  United States. Department of Transportation. Research and Special Programs Administration
• Subject/TRT Terms:
  • Asphalt pavements
  • Asphalt additives
  • Asphalt rubber
  • Recycling
  • Waste products (Materials)
  • Hot mix asphalt
  • Pavements, Asphalt--New Jersey--Additives
  • Asphalt-rubber
  • Tires--Recycling
  • Waste products as road materials--New Jersey
• Resource Type:
  Tech Report
• Geographical Coverage:
  New Jersey
• Edition:
  Final report; Sept. 2003-July 2004.
• Corporate Publisher:
  Rutgers University. Center for Advanced Infrastructure and Transportation
• Abstract:
  An asphalt-rubber hot mix asphalt (AR-HMA) design was created using a Superpave 12.5mm gradation and a #30 (-) mesh ; crumb rubber at 20% total weight of the asphalt binder. At this point in time, asphalt rubber has only been used with HMA ; that contains a more open graded nature, such as open graded friction course (OGFC). However, OGFC is limited on it use ; due to its potential problems (i.e. clogging and winter maintenance). However, a 12.5mm Superpave mix may be used on ; almost any roadway in New Jersey and is most commonly found as the surface course. It is used for both new construction ; and rehabilitation projects. Therefore, this mix type has the largest potential for usage, meaning that more tires can ; eventually be recycled. However, two factors need to be considered prior to acceptance; performance and cost. ; Four HMA mixes were constructed and tested in this study. Three baseline mixes using a PG64-22, PG70-22, and a PG76- ; 22 asphalt binder, as well as the AR-HMA mix which used crumb rubber blended with the same PG64-22 asphalt binder. ; The influence of crumb rubber particle size on the compaction properties during the mixture design procedure was also ; evaluated. This would provide a method of comparing the final mixture performance of different performance graded ; binders to the AR-HMA mix. This type of methodology of testing the mixtures is extremely important due to the necessity ; of ensuring the crumb rubber complying to the aggregate gradation volume limitations, and how the crumb rubber interacts ; with this volume limitation under performance testing. Therefore, a number of different performance tests were conducted ; on the four different HMA mixes: 1) Asphalt Pavement Analyzer, 2) Repeated Load Permanent Deformation testing using ; the Simple Performance test specifications, 3) Dynamic Modulus, 4) Repeated Shear at Constant Height, 5) Frequency ; Sweep at Constant Height,and 6) Simple Shear at Constant Height. ; The results from the mixture design portion concluded that to provide consistent compactibility when using crumb rubber in ; a 12.5mm Superpave design, the maximum particle size should not be greater than a #30 mesh. The performance tests ; concluded that the AR-HMA mix performed as well as or better than the PG76-22 for every test conducted. For example, ; the dynamic modulus test results showed that the AR-HMA had similar stiffnesses to the PG76-22 at the high test ; temperatures, however, the AR-HMA had a much less stiffness at the low test temperature. This indicates that the ARHMA ; mix design in this study will provide excellent rut resistance, while also providing excellent low temperature cracking ; resistance. Essentially, by adding the crumb rubber to the PG64-22, the working temperature range of the asphalt binder ; increased on both the high and low sides. Also, by performing similarily to the PG76-22, Bayshore Recycling now can ; establish a cost comparison using the difference in cost between a HMA with a PG64-22 and a PG76-22.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18363/dot_18363_DS1.pdf
• File Type:
  [PDF - 1.81 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:84c22a56c14c0767a20c8e28abdd9d2692f3b65ebae08e6813a817ef51abbc51