Evaluation of repeatability of Kansas test method KT-73, "density, absorption and voids in hardened concrete," boil test.

Details

• Creators:
  Montney, Rodney A. ; Barker, Susan F.
• Corporate Creators:
  Kansas. Dept. of Transportation. Bureau of Materials & Research
• Subject/TRT Terms:
  • Concrete
  • Permeability
  • Quality control
  • Durability tests
  • Test procedures
  • Evaluation
• Publication/ Report Number:
  KS-15-04
• Resource Type:
  Tech Report
• Geographical Coverage:
  Kansas
• Corporate Publisher:
  Kansas. Dept. of Transportation. Bureau of Materials & Research
• Abstract:
  For years, the Kansas Department of Transportation (KDOT) and concrete producers in the state have used a ; Rapid Chloride Test for concrete cylinders, AASHTO T277. This test has been thought of as an appropriate quality ; control test to evaluate permeability in concrete. Unfortunately, it has a low repeatability—a 51% difference in the ; mean between two laboratories/operators as percent of the mean (AASHTO T277, 2011). This could mean the ; difference between reliable permeability results and questionable results. This has a direct impact on KDOT’s ability to ; judge the quality of the concrete mixture, and whether it will be a long-term durable concrete or a concrete that fails ; early. ; KDOT has also used the Kansas Test Method KT-73 (2012), Density, Absorption and Voids in Hardened ; Concrete, a permeability test commonly referred to as the Boil Test, to evaluate concrete durability in the state of ; Kansas. It covers the determinations of density, percent absorption, and percent permeable voids in hardened concrete. ; KT-73 reflects testing procedures found in ASTM C642 (2013). KDOT has relied on this test to evaluate concrete ; permeability, but some concrete producers in the state have objected to its accuracy, preferring the Rapid Chloride Test ; which has a low repeatability. In 2009, with the help of several ready mix producers and private laboratories, KDOT ; conducted a round robin evaluation of KT-73. ; The results of this round robin showed that the KT-73 Boil Test could be repeated with a fairly high degree of ; precision. This study demonstrates that the expected range between two properly conducted tests at different ; laboratories should not be more than 8% of the average. The repeatability of the Boil Test is significantly better than ; the repeatability of the Rapid Chloride Test for concrete cylinders, AASHTO T277 (2011), which many concrete ; producers have relied on to verify their concrete’s durability. The Boil Test and the Rapid Chloride Test take about ; equal amounts of time to perform, but the equipment required for the Boil Test is significantly less expensive. Thus, ; the Boil Test is not only less expensive to perform, but is a better indicator with respect to reliability of the ; permeability and durability of concrete used in the state of Kansas.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29077/dot_29077_DS1.pdf
• File Type:
  [PDF - 1.03 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:8dbe3c88526aae8fcd3a6e1e009d1068c884bdc6a63ce95100b5f54029dc687c