Field Structural Performance of Stabilized Blended Calcium Sulfate Materials Under Accelerated Pavement Testing

Louisiana has used a recycled fluorogypsum mixture known as blended calcium sulfate (BCS) for more than a decade as a pavement base layer. Moisture susceptibility is the major concern of raw BCS use as a pavement structural layer without further chemical stabilization. Both long-term performance problems and short-term construction difficulties could be caused by such use. Three accelerated pavement test sections were recently tested at the Louisiana Pavement Research Facility in Port Allen, Louisiana, including two of different BCS bases and one of a crushed stone base, in order to verify BCS stabilization scheme efficiency as obtained from laboratory results, as well as to further assess field performance of stabilized BCS materials and potential cost benefits. A common pavement structure was shared by the three sections, the only difference being base course materials. Instrumentation of each test section consisted of one multi-depth deflectometer and two pressure cells for measuring related pavement responses. At the end of every 25,000 load repetitions, falling weight deflectometer (FWD) and surface distress survey tests were performed. The overall accelerated loading results indicated that a test section containing a BCS base stabilized by granulated ground blast furnace slag (GGBFS) outperformed, by a significantly large margin, the other two sections. FWD backcalculation results indicated that BCS base stabilized by GGBFS generally possessed a higher in-situ modulus value than an asphalt concrete layer did, and that it performed like a lean concrete. There was further indication, by cost benefit analysis results, that in a flexible pavement design using a GGBFS stabilized BCS in lieu of a stone base, the asphalt concrete thickness could be considerably reduced, enabling immediate saving of construction costs.

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  • Authors:
    • Wu, Zhong
    • Chen, Xingwei
    • Mohammad, Louay N
    • Zhang, Zhongjie
  • Publication Date: 2009-5


  • English

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  • Accession Number: 01145206
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 4 2009 4:26PM