Precast, Prestressed Concrete Bent Caps: Volume 1 Preliminary Design Considerations and Experimental Test Program

Precast prestressed concrete bent caps may provide significant benefits by enabling accelerated construction of bridge substructures and improve longevity by reducing the propensity for cracking. The Texas Department of Transportation enables the use of precast reinforced concrete (RC) bent caps through standard connection details that allow contractors the option of cast-in-place or precast caps. A largely unrealized benefit of precast caps is the use of prestressing to enable additional fabrication options and to reduce or eliminate cracking. To enable widespread use, the design and behavior of pretensioned bent caps is explored through a comprehensive study consisting of a literature review, a design study, experimental tests, and with a discussion of the results. Design for flexure is based upon the concept of zero tensile stresses under dead loads, thereby ensuring any cracks close upon removal of live loads. A modified pocket connection is designed to improve constructability and minimize the potential negative effects of prestressing at the reduced cross-section. Full-scale bent caps were tested under indeterminate loads representative of those in multicolumn bents. An RC specimen was designed, constructed, and tested to serve as a performance baseline. Pretensioned caps investigate the spacing of shear spacing, use of voids, and void detailing. Pretensioned caps exhibit significantly reduced flexure cracking, with the ability to fully close upon removal of live load. Bent caps with voids were susceptible to minor shear cracking under design loads, with minimal impact of void detailing. Pocket connections provided adequate performance under design loads. The experimental findings validate the design and construction concepts, which may be useful in developing design and construction recommendations.

• Dataset URL:
  • https://doi.org/10.18738/T8/HXPWMG
• Dataset URL:
  • https://library.ctr.utexas.edu/Presto/search/SearchResults.aspx?q=(catalog.ID%3a(36004))
• Record URL:
  • http://tti.tamu.edu/documents/0-6863-R1-Vol1.pdf
• Summary URL:
  • https://library.ctr.utexas.edu/Presto/catalogid=35898
• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/35429
• Dataset URL:
  • https://rosap.ntl.bts.gov/view/dot/58426
• Supplemental Notes:
  • Supporting datasets available at: https://doi.org/10.18738/T8/HXPWMG; https://library.ctr.utexas.edu/Presto/catalogid=36004; https://rosap.ntl.bts.gov/view/dot/58426
• Corporate Authors:

  Texas A&M Transportation Institute

  Texas A&M University System
  3135 TAMU
  College Station, TX  United States  77843-3135

  Texas Department of Transportation

  Research and Technology Implementation Office
  125 E 11th Street
  Austin, TX  United States  78701-2483

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Birely, Anna C
  • Mander, John B
  • Lee, Ju Dong
  • McKee, Codi D
  • Yole, Kevin J
  • Barooah, Usha R
• Publication Date: 2018-4

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Technical Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 320p

Subject/Index Terms

• TRT Terms: Bents; Bridge construction; Bridge substructures; Cracking; Flexure; Precast concrete; Prestressed concrete; Serviceability; Shear strength; Structural design; Tension
• Uncontrolled Terms: Pier caps
• Subject Areas: Bridges and other structures; Construction; Design; Highways; Maintenance and Preservation; Materials;

Filing Info

• Accession Number: 01667060
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-18/0-6863-R1-Vol1
• Contract Numbers: Project 0-6863
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Apr 25 2018 11:14AM