Allowable compressive stress at prestress transfer.

Details

• Creators:
  Schnittker, Brian ; Bayrak, Oguzhan
• Corporate Creators:
  University of Texas at Austin. Center for Transportation Research
• Corporate Contributors:
  Texas. Dept. of Transportation. Research and Technology Implementation Office ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Self compacting concrete
  • Compressive strength
  • Box beams
  • Beams
  • Box girders
  • Concrete bridges
  • Allowable release stress
  • compressive stress limit
  • prestress transfer
  • self consolidating concrete
  More +
• Publication/ Report Number:
  FHWA/TX-09/0-5197-4
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas
• Corporate Publisher:
  Texas Department of Transportation. Research and Technology Implementation Office
• Abstract:
  In 2004, The Texas Department of Transportation initiated Project 5197 to investigate the feasibility of ; increasing the allowable compressive stress limit at prestress transfer. Initially, the live load performance of 36 ; specimens was evaluated by Birrcher and Bayrak (TxDOT Report 5197-1, 2007). Report 5197-4 presents the ; subsequent research conducted based on recommendations of Birrcher and Bayrak (2007). In this portion of ; TxDOT Project 5197, 45 Type-C beams and 10 4B28 box beams were tested to experimentally determine their ; cracking load. The Type-C beams were produced in four different fabrication plants using conventionally ; consolidated concrete. The 10 4B28 box beams were produced in two fabrication plants using concrete mixture ; designs of both self consolidating concrete as well as conventional concrete. For all specimens, measured ; cracking loads were compared to predicted cracking loads. The data from the 45 Type-C beams and 10 box ; beams were added to the 36 beams investigated by Birrcher and Bayrak (2007) to compile a comprehensive set ; of data from 91 specimens. An appropriate maximum compressive stress limit was determined from the ability ; to accurately predict the load at which cracking occurred. As the maximum compressive stress at prestress ; transfer was increased, a decline in cracking load prediction accuracy was observed. For the specimens subjected ; to high compressive stresses at release (greater than 0.65f’ci), the concrete in the pre-compressed tensile zone was ; subjected to the non-linear inelastic range causing microcracking to occur. This non-linear behavior (due to ; microcracking) was unaccounted for in prestress losses or standard design equations (P/A±Mc/I). Based on the ; analysis of the results, an increase of the allowable compressive stress limit at prestress transfer to 0.65f’ci is ; justified. Additionally, the use of self consolidating concrete with a maximum compressive stress of 0.65f’ci is ; not recommended.
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• Format:
  PDF
• Funding:
  0-5197
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/16780/dot_16780_DS1.pdf
• File Type:
  [PDF - 7.96 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:024ebc48227067b735f899e52495fce136febc76d39df3069cbb78ce84144c82