Prestress Losses in UHPC and Hybrid Precast, Prestressed Bridge Girders

Details

• Creators:
  Yadak, Omar ; Floyd, Royce W. ; Volz, Jeffery S.
• Corporate Creators:
  University of Oklahoma. School of Civil Engineering and Environmental Science
• Corporate Contributors:
  Innovative Bridge Technologies/Accelerated Bridge Construction (IBT/ABC) Tier-1 University Transportation Center (UTC) ; United States. Department of Transportation. University Transportation Centers (UTC) Program ; United States. Department of Transportation. Office of the Assistant Secretary for Research and Technology
• Subject/TRT Terms:
  • Ultra high performance concrete
  • Prestressed concrete
  • Losses
  • Precast concrete
  • Girders
  • Bridges
  • Hybrid
• Publication/ Report Number:
  IBT/ABC-UTC-2024-C1-OU01-Final
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report (January 2024 - May 2025)
• Corporate Publisher:
  Innovative Bridge Technologies/Accelerated Bridge Construction (IBT/ABC) Tier-1 University Transportation Center (UTC)
• Description:
  This project evaluated long-term performance of precast/prestressed ultra-high performance concrete (UHPC) and hybrid UHPC-conventional self-consolidating concrete (SCC) bridge girders. The objectives of the research were to measure prestress losses and evaluate the effectiveness of different design details for mitigating stresses in the girder end region including their effect on hybrid girder capacity. Ten approximately half-scale AASHTO Type-II prestressed concrete girder specimens were cast, instrumented, and monitored over time to measure immediate and time-dependent prestress losses. These included one SCC specimen, three full UHPC specimens, five hybrid specimens consisting of SCC with UHPC in one end region, and one specimen consisting of a stay-in-place UHPC formwork shell and conventional concrete infill. UHPC mix designs developed at OU through funding by ODOT and ABC-UTC were utilized in this study. Different design details developed for reducing stresses and mitigating cracking in the end region of prestressed girders were also evaluated in the hybrid girders to determine the effects on girder performance. Five hybrid prestressed girders were successfully cast with a bi-fluid interface. The use of a wooden divider at the interface between UHPC and SCC helped to control the flow rate of the UHPC and SCC and maintain the two materials separated until the casting process was done. The UHPC end regions for all the hybrid prestressed girders had higher compressive stress compared to the SCC end regions, no cracks were observed in those end region after 150 days. However, some cracks were observed at the SCC end regions for some of the hybrid prestressed girders and the SCC girder. The time-dependent (creep and shrinkage) prestress losses behavior of the hybrid prestressed girders was similar to that of the SCC prestressed girder and full UHPC prestressed girders, indicating that the hybrid design did not appear to have an impact on the prestress losses at midspan. The length of the overall UHPC section in the hybrid prestressed girder did not have an effect on prestress loss behavior at midspan and the UHPC durability to withstand high compressive stresses at the end region.
• Format:
  PDF
• Funding:
  69A3552348322
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/94048/dot_94048_DS1.pdf
• File Type:
  [PDF - 2.43 MB]
• Collection(s):
  University Transportation Centers
• Main Document Checksum:
  urn:sha-512:0c7346e5f7fbcbc81a4bcbc3ee3bf3528233a376f335a35a13ec9fe0e6fb6f882a50c7a99f9b669b216012945ef58e26ec1221ded90b2b5e8789d5aedb9ae4fc