Bond Performance Between Precast UHPC Substrates and Field-Cast UHPC Connections

Details

• Creators:
  Lau, Kingsley ; Permeh, Samanbar ; Garber, David
• Corporate Creators:
  Florida International University
• Corporate Contributors:
  Florida. Department of Transportation
• Subject/TRT Terms:
  Bonding Casting Corrosion Fibers Interfaces Interface Shear Match Precast Concrete Shear Properties Structural Connection Ultra High Performance Concrete Wetting

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• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Draft Final Report: February 2022 - June 2026
• Corporate Publisher:
  Florida. Department of Transportation
• Abstract:
  Ultra-high performance concrete (UHPC) has been used in different applications and was explored to be used for precast elements; however, there was limited research and guidance on the connection between UHPC elements. General test methods to evaluate interface strength (e.g., direct tension pulloff, shear pushoff) can be used with the Mohr-Coulomb Friction Approach to determine the cohesion coefficient and coefficient of friction typically used to estimate interface shear strength. The test program here sought to explore the bond behavior of matchcast UHPC with various interface surface conditions, such as surface roughness (including smooth faces cast on plywood formwork, roughened surfaces created by casting on form liners) and exposed steel fibers at the interface (created by the use of paste retarders) in order to inform design provisions for matchcast UHPC. The effect of pre-corroded steel fibers and the surface wetting conditions were considered as well. Trends in interface shear behavior associated with surface conditions were identified. The most evident outcome from testing was that the presence of exposed steel fibers provided improved performance relative to only roughened surfaces. Roughened interfaces can improve the friction of the interface, but the presence of the exposed fibers improved both cohesive strength and provided improvement to the post-crack tensile strength. Additionally, there was improved cohesive bonding when prolonged wetting by burlap was made. Extended term ponding had reduced performance. Cohesion coefficient and friction factors for the various test conditions were assessed. Modification to interface shear strength provisions to include the effect of wetting conditions on cohesion was presented. The experimental work provided practical experiences that were translated into considerations for construction.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:6801ac94b5f3aac03390b1dd9e8a8e3f07f3f89c1c0a779940d055cede52b012e779aeee3a8d1c033d0e7ce8277d8309faa2a435b116b0443b5e9b1063aec322
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/92912/dot_92912_DS1.pdf
• File Type:
  [PDF - 10.37 MB ]