Hybrid Prestressed Concrete Bridge Girders using Ultra-High Performance Concrete

In prestressed bridge girders, end region reinforcement and strand debonding are used to control cracking caused by high tensile stresses that occur due to prestress transfer. In some cases, these measures do not effectively control cracking, resulting in construction delays, potential repairs, additional costs, and potential compromise of long-term durability. Ultra-High Performance Concrete (UHPC) is an attractive solution to prevent end region cracking and potentially increase girder span lengths. This approach consists of producing a hybrid girder in which UHPC is placed at the end of the girder and conventional self-consolidating concrete (SCC) mixture placed in the remainder of the girder. This approach strategically places the higher cost and higher strength material in the portion of the beam with most extreme stress conditions during construction. To evaluate the effectiveness of UHPC, experimental and analytical investigations were conducted. The experimental program covered five 20-ft-long Florida-I 72 beam (FIB 72) mockups made of SCC and UHPC and two 50-ft-long Florida-I 54 beam (FIB 54) UHPC-SCC hybrid girders used to evaluate end region behavior and strength under applied shear. Cracking and strain data were collected during prestress transfer, and one year after transfer. Variables considered in these specimens included UHPC length from the girder end and amount of end region reinforcement. The experimental results of the FIB 72 mockups indicated that UHPC ends exhibited maximum end region crack widths of 0.003 in., which were ~25% of the crack widths in the SCC ends. Load tests on UHPC-SCC FIB 54 hybrid girder indicated shear strengths significantly higher than comparable SCC girders. Furthermore, the UHPC-SCC interface performed well during load tests, thereby validating the methods of construction. The analytical program was conducted in three stages: (1) Material model identification and calibration, (2) Development and validation of FIB 72 mockup model for end region evaluation, and (3) development and validation of FIB 54 hybrid girder model under shear loads. The results from the analytical work confirmed that UHPC is a promising approach to reducing end region cracking.

• Record URL:
  https://fdotwww.blob.core.windows.net/sitefinity/docs/default-source/research/reports/fdot-bdv31-977-101-rpt.pdf?sfvrsn=4bb50c39_4
• 
• Summary URL:
  https://fdotwww.blob.core.windows.net/sitefinity/docs/default-source/research/reports/fdot-bdv31-977-101-sum.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/59878
• Corporate Authors:

  University of Florida, Gainesville

  Department of Civil and Coastal Engineering
  Gainesville, FL  United States  32611-6580

  Florida Department of Transportation

  605 Suwannee Street
  Tallahassee, FL  United States  32399-0450
• Authors:
  • Torres, Eduardo
  • Hamilton, H R
  • Consolazio, Gary R
• Publication Date: 2020-12

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 211p

Subject/Index Terms

• TRT Terms: Bridge construction; Composite construction; Cracking; Girder bridges; Girders; Prestressed concrete bridges; Self compacting concrete; Shear strength; Ultra high performance concrete
• Geographic Terms: Florida
• Subject Areas: Bridges and other structures; Construction; Highways; Materials;

Filing Info

• Accession Number: 01772411
• Record Type: Publication
• Report/Paper Numbers: UF Project No. P0086443 & P0086444
• Contract Numbers: BDV31-977-101
• Files: NTL, TRIS, ATRI, STATEDOT
• Created Date: May 25 2021 3:12PM