PHOSPHOGYPSUM SLAG AGGREGATE-BASED ASPHALTIC CONCRETE MIXES

Phosphogypsum (PG) is a powderlike, industrial by-product that results from the production of phosphoric acid used in the fertilizer and chemical industries. Large production rates and the associated stockpiling problems have led researchers to seek alternative uses for PG--primarily as a construction material. By extracting sulfur dioxide from the PG for the production of sulfuric acid, a by-product slag aggregate is generated in the process. This study examines the feasibility of using this slag aggregate in asphaltic concrete binder course mixes. Physical properties of the slag aggregate, such as gradation, specific gravity, absorption, unit weight, and void content were determined, as well as durability and environmental characteristics. The Marshall mix design method was employed to obtain the optimum asphalt content for this aggregate, while moisture susceptibility was investigated by the boiling and modified Lottman tests. Aggregate performance potential was assessed via indirect tensile, resilient modulus, and dynamic creep tests that were performed on the mix. The study findings indicate that PG-based slag aggregate can be used successfully in asphaltic concrete binder course mixtures.

Language

  • English

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Filing Info

  • Accession Number: 00726106
  • Record Type: Publication
  • Files: TRIS, ATRI
  • Created Date: Sep 25 1996 12:00AM