Influence of Rock Salt Impurities on Limestone Aggregate Durability

Non-durable coarse aggregate in concrete pavement can break down under repeated freeze-thaw cycles. Application of rock salt may increase the severity of exposure conditions because of trace compounds, such as calcium sulfate, in rock salt. Concrete and saw-cut limestone specimens were also subjected to wet-dry cycles in varying salt solutions to examine the influence of trace compounds in rock salt. Subsequently, limestone aggregate in concrete was subjected to freeze-thaw cycling in two methods: salt-treating the aggregate before batching concrete, and half-immersing concrete specimens in rock salt solution during freeze-thaw cycling. The wet-dry testing of cut limestone was not severe enough to determine the effects of trace compounds in salt solution. Preliminary experiments showed that salt-treating the aggregates before batching concrete showed more promise in differentiating aggregate quality or in gaining insights into concrete pavement performance. Concrete prisms were made using 12 different salt-treated aggregates and were tested according to Kansas Test Method KTMR-22 (2006) and additionally ASTM C666 (2008) using Method A. Companion prisms were made using the same aggregates without salt treatment and were tested using the same two freeze-thaw test methods. Use of saw-cut limestone prisms for testing the freeze-thaw durability of concrete aggregates is not recommended as crushing limestone may change its properties, prisms from the same source have variable quality, and prisms are labor-intensive to make. Further testing should be conducted to validate the potential use of ASTM C666 Method A as a method to achieve similar freeze-thaw acceptance results as Method B in fewer freeze-thaw cycles. Freeze-thaw tests of concrete made with aggregates presoaked in salt brine could provide a good method to test the effects of salt exposure on internal freeze-thaw distress on the paste portion of the concrete. However, salt treatment may not be an effective method to use for coarse aggregate qualification.

• Record URL:
  http://dmsweb.ksdot.org/AppNetProd/docpop/docpop.aspx?clienttype=html&docid=9649156
• Summary URL:
  http://dmsweb.ksdot.org/AppNetProd/docpop/docpop.aspx?clienttype=html&docid=9649157
• Corporate Authors:

  Kansas State University Transportation Center

  Kansas State University
  Department of Civil Engineering
  Manhattan, KS  United States  66506

  Kansas Department of Transportation

  Bureau of Research
  2300 SW Van Buren Street
  Topeka, KS  United States  66611-1195
• Authors:
  • Riding, Kyle A
  • Varner, Jonathan
  • Armstrong, Cale
• Publication Date: 2016-8

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 162p

Subject/Index Terms

• TRT Terms: Coarse aggregates; Concrete pavements; Deicing chemicals; Freeze thaw durability; Freeze thaw tests; Halite; Limestone aggregates; Pavement performance
• Subject Areas: Highways; Maintenance and Preservation; Materials; Pavements;

Filing Info

• Accession Number: 01608658
• Record Type: Publication
• Report/Paper Numbers: K-TRAN: KSU-12-6
• Contract Numbers: C1913
• Files: TRIS, ATRI, STATEDOT
• Created Date: Aug 29 2016 11:10AM