ULTRA-THIN WHITETOPPING

Ultra-thin whitetopping (UTW) is a process in which 2-4 in. of portland cement concrete, typically fiber reinforced, is placed over a prepared surface of distressed asphaltic concrete. UTW results in a composite pavement system, delivering the long life and superior performance characteristics of concrete pavement at an initial construction cost competitive with ordinary asphaltic concrete overlay. The system has demonstrated a lower life cycle cost because of fewer maintenance requirements and lower frequency of replacement. The success of UTW is attributed to two factors: the thin concrete overlay, which bonds to existing asphalt and creates a monolithic section, and the use of short joint spacings. The bond at the concrete-asphalt interface creates a composite section, and both materials contribute to the load-carrying capacity of the entire structure. Short joint spacings allow the load to be carried with lower deflection, and joint movement is minimized as well. A normal UTW mix design includes cementitious materials, coarse and fine aggregates, water, admixtures, and fibers. Specified admixtures include an air-entraining agent and frequently a water reducer. UTW projects typically contain polypropylene fibers. The primary disadvantage to UTW during construction is the large number of joints. There have also been instances where the ride quality has been poor.

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  • Corporate Authors:

    Civil Engineering News, Incorporated

    1255 Roberts Boulevard, Suite 230
    Kennesaw, GA  United States  30144
  • Authors:
    • Adams, F
  • Publication Date: 2000-8

Language

  • English

Media Info

  • Features: Photos;
  • Pagination: p. 66-67
  • Serial:
    • Civil Engineering News
    • Volume: 12
    • Issue Number: 7
    • Publisher: Civil Engineering News, Incorporated
    • ISSN: 1051-9629

Subject/Index Terms

Filing Info

  • Accession Number: 00798370
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 9 2000 12:00AM