Evaluation of Prestressing Strand Bond with Type IL Cement

The proposed research is a 3-phase approach aimed at understanding the reduced bonding capacity of prestressing strands when limestone cements are used. Task 1: Conduct strand bond pullout tests in a cement grout. Since the essence of the observed reduction in strand bond is due to the direct interaction between the cement paste and strand, initial testing will quantify the difference in bond of strand that is embedded in a grout made with Type IL cements with varying limestone contents. The ASTM A981 test methodology, listed in the Supplemental requirements of ASTM A416, will be utilized in this test phase. The tests will be conducted with grouts utilizing pure Type I cement (baseline tests), plus grouts with Type IL cements having a 5%, 10%, 15%, and 20% limestone substitution by weight. Although ASTM C595 currently limits Type IL cement to a limestone content of 15%, there will likely be higher limestone contents allowed in the not-too-distant future. Task 2: Conduct bond pullout tests with concrete. Additional pullout tests utilizing specimens with aggregate will be performed with cements having varying limestone content as in Phase 1. These results will then be directly comparable to the results in Phase 1 to see how the addition of aggregate influences the bond. The ASTM A1081 test methodology will be used in this phase of the study, except that Type I and Type IL cement will be used instead of the standard (Type III) cement. The ASTM A1081 and A981 tests both use the same 5”-diameter steel cans and a 16” embedment length. Task 3: Pretensioned Concrete Beam Investigation. A limited laboratory investigation will be conducted to determine the effect of using Type IL cement on the transfer length in pretensioned concrete members. This phase will include the fabrication of pretensioned concrete members using concrete mixtures with both a Type I and Type IL cement. The resulting transfer lengths for 7-wire strand will then be directly compared with current Kansas Department of Transportation (KDOT) design assumptions.

    Language

    • English

    Project

    • Status: Active
    • Funding: $99,781.00
    • Contract Numbers:

      RE-0902-01

      C2237

      K-TRAN: KSU-25-1

    • Sponsor Organizations:

      Kansas Department of Transportation

      Eisenhower State Office Building
      700 SW Harrison Street
      Topeka, KS  United States  66603-3754
    • Performing Organizations:

      Kansas State University Transportation Center

      Kansas State University
      Department of Civil Engineering
      Manhattan, KS  United States  66506
    • Principal Investigators:

      Peterman, Robert

      Panchmatia, Parth

    • Start Date: 20240701
    • Expected Completion Date: 20251231
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01942494
    • Record Type: Research project
    • Source Agency: Kansas Department of Transportation
    • Contract Numbers: RE-0902-01, C2237, K-TRAN: KSU-25-1
    • Files: RIP, STATEDOT
    • Created Date: Jan 13 2025 2:35PM