Controlling conductivity of asphalt concrete with graphite.

Details

• Creators:
  Park, Philip ; Rew, Younho ; Baranikumar, Aishwarya
• Corporate Creators:
  Texas A&M Transportation Institute
• Corporate Contributors:
  Southwest Region University Transportation Center (U.S.) ; United States. Dept. of Transportation. Research and Innovative Technology Administration
• Subject/TRT Terms:
  • Asphalt concrete
  • Graphite
  • Electrical conductivity
  • Mix design
  • Binders
  • Percolation
  • Tensile strength
  • Aggregate gradation
• Publication/ Report Number:
  SWUTC/14/600451-00025-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Corporate Publisher:
  Texas A&M Transportation Institute
• Abstract:
  Electrically conductive asphalt concrete has a huge potential for various multifunctional applications such as ; self-healing, self-sensing, and deicing. In order to utilize the full spectrum of applications of electrically conductive ; asphalt composites, precise control of the asphalt mixture resistivity is needed. Most of the previous research using ; conductive fibers as the primary conductive additives observed a sudden transition from the insulated to conductive ; phase, commonly known as the percolation threshold, which obstructs more precise conductivity control. Aiming to ; control the electrical conductivity of asphalt concrete with a smooth transition from the insulated to conductive ; phase, the researchers have selected graphite powders as an alternative conductive additive in this study. Nine types ; of graphite having different particle shape, size, and origin were mixed with asphalt binders, and their effects on ; imparting conductivity were investigated. Based on the results, the research team selected two types of graphite and ; evaluated the effects on the electrical conductivity of asphalt concrete. The team also examined the effects of ; aggregate gradation, binder content, and binder type. ; The results showed that the electrical conductivity of asphalt mastic is sensitive to the graphite type. The ; natural flake graphite is effective to mitigate the percolation threshold, and a sufficiently high conductivity can be ; achieved by replacing a part of the fillers with graphite (the conductivity ranged from 10−6 ; to 10−2 ; /Ω•cm). The results ; also showed that the binder type does not make a significant change in the mixture conductivity, but the aggregate ; gradation brings approximately two order differences in the volume resistivity. Mechanical performance of the ; conductive asphalt is also an important factor for practical field applications. The indirect tension test results showed ; that the addition of graphite improves the indirect tensile strength up to 41 percent. The electrical and mechanical ; data obtained from this study provide essential information on the selection of graphite type and asphalt mixture ; design to achieve the proper electrical conductivity required for the probable multifunctional applications of asphalt ; concrete, which will lead to technical innovations for sustainable pavements.
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• Format:
  PDF
• Funding:
  DTRT12-G-UTC06
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28218/dot_28218_DS1.pdf
• File Type:
  [PDF - 3.63 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:6cd08cbe5b61847bd00622750dfc2b93d02d5f3a395a23e9093574b2232f62bd