Studies of the Thermal Transformation of Synthetic Aggregates Produced in a Rotary Kiln

Details

• Creators:
  Houston, James T. ; Blank, Horace R. ; Kunze, George W.
• Corporate Creators:
  University of Texas at Austin ; Texas Transportation Institute. Texas A&M University
• Corporate Contributors:
  Texas Highway Department ; United States. Department of Transportation. Federal Highway Administration. Bureau of Public Roads
• Subject/TRT Terms:
  • Aggregates
  • Synthetics
  • Artificial aggregates
  • Cement kilns
  • Clay minerals
  • Differential thermal analysis
  • Diffraction
  • Ovens
  • Thermal analysis
• Publication/ Report Number:
  81-9
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas ; United States
• Corporate Publisher:
  Texas Transportation Institute. Texas A&M University
• Abstract:
  The wide variations found in the properties of synthetic aggregates made from clay-type materials may be due in large part to differences in the degree of thermal transformation of their constituents resulting from processing in rotary kilns. In order to study this problem, two different clays were processed in a research rotary kiln under different conditions of temperature and retention time. For each material, firing conditions were planned to yield two groups of aggregates, one heavy (more than 55 lbs. per cu. ft.) and one light (less than 55 lbs. per cu. ft.). The raw clays and the resulting aggregates, as well as a commercial synthetic aggregate for comparison, were investigated by X-ray diffraction, differential thermal analysis (DTA), effluent gas analysis (EGA), and gas chromatography (GC). This combination of methods yielded useful information concerning the extent of the transformation of the clay minerals into new crystalline substances, the elimination of impurities (such as organic matter, carbonates, and sulfur compounds), and the gases responsible for bloating. From this information the poorly burned aggregates could be identified.
• Format:
  PDF
• Funding:
  2-8-65-81
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/84499/dot_84499_DS1.pdf
• File Type:
  [PDF - 2.36 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:447a3da1783cf479ecd038227e7eadd7a0cd5df8cb802d43b059614aacf3d42759c4b30f4d45add36207c19caf49591ddb6f0d64320087b8af7d4a7d2255378e