Strengthening dapped ends of precast double tees with externally bonded FRP reinforcement

William J. Gold, Gregg J. Blaszak, Matt Mettemeyer, Antonio Nanni, Michael D. Wuerthele

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


A 90,000 square meter, three-story, precast concrete parking garage in Pittsburgh, PA was strengthened in order to address concerns regarding distress in the double tee beams supporting each elevated floor. Initially, the distress was manifest in inclined cracks forming at the reentrant corner of the dapped ends. During an independent load test of sample tees, additional cracks at approximately 1.5 m from the dapped end formed and became so severe that, at roughly 75% of the design load, the tees were deemed to have failed. This failure condition resulted in an effort to strengthen the ends of the tees in the garage for shear and flexure. In assessing various strengthening alternatives, externally bonded carbon fiber reinforced polymer (FRP) reinforcement was determined to be the most cost effective, the least disruptive to the operation of the parking garage, and virtually unnoticeable once the installation was complete. A load test of several tees after the installation of the FRP reinforcement demonstrated that the retrofitted tees could support loads over 100% of the design load. This paper presents the details of the design, specification, installation, and testing of the FRP strengthening system for this large retrofit project.

Original languageEnglish (US)
Title of host publicationStructures Congress 2000
Subtitle of host publicationAdvanced Technology in Structural Engineering
StatePublished - 2004
Externally publishedYes
EventStructures Congress 2000: Advanced Technology in Structural Engineering - Philadelphia, PA, United States
Duration: May 8 2000May 10 2000

Publication series

NameStructures Congress 2000: Advanced Technology in Structural Engineering


OtherStructures Congress 2000: Advanced Technology in Structural Engineering
Country/TerritoryUnited States
CityPhiladelphia, PA


  • Concrete structures
  • Concrete, reinforced
  • Fiber reinforced plastics
  • Parking facilities
  • Reinforcement

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Mechanics of Materials
  • Safety, Risk, Reliability and Quality
  • Building and Construction


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