MEASUREMENT OF TRANSFER LENGTH ON PRESTRESSING STRANDS IN PRESTRESSED CONCRETE SPECIMENS. INTERIM REPORT
On October 26, 1988, the Federal Highway Administration (FHWA) issued a memorandum disallowing the use of 0.6-inch-diameter strand in pretensioned application. Recent studies had indicated that current AASHTO provisions for the transfer length and development length of 0.6-inch prestressing strand were unconservative. On the basis of very limited data, restrictions on 0.6-inch strand were adopted as an interim measure until additional research results were available to either substantiate or restructure code provisions. In reponse to this research need, this report focuses on determining the transfer length of 0.5-inch and 0.6-inch strand. Sixty-two transfer length specimens were cast and tested. Of these, 26 were single-strand specimens. Eighteen were three-strand specimens, and six were five-strand specimens. Fifty specimens had rectangular cross sections with concentric prestressing. The remaining twelve sections were I-shaped, designed to resemble the cross section for an AASHTO girder. Research variables included the number of strands, strand spacing (2-inch or 2.25-inch), strand diameter (0.5-inch or 0.6-inch), and the effects of transverse reinforcement. The transfer length of debonded strand was also studied. Overall, test results indicated that the behavior of 0.6-inch strand is very similar to the behavior of the 0.5-inch strand. Furthermore, the transfer lengths of both 0.5-inch and 0.6-inch strand are closely predicted by AASHTO/ACI provisions.
- Research study title: Influence of Debonding of Strands on Behavior of Composite Prestressed Concrete Bridge Girders.
University of Texas, AustinCenter for Transportation Research, 3208 Red River Street
Austin, TX United States 78705
Austin, TX United States 78763
Washington, DC United States 20590
- Unay, I O
- RUSSELL, B
- Burns, N
- Kreger, M
- Publication Date: 1991-3
- Features: Appendices; Figures; References; Tables;
- Pagination: 150 p.
- TRT Terms: Cracking; Debonding; Diameter; Girder bridges; Laboratory tests; Prestressed concrete; Prestressing; Spacing; Time duration; Transfers; Transverse reinforcement
- Uncontrolled Terms: Prestressing strands; Transfer length
- Old TRIS Terms: Test results
- Subject Areas: Bridges and other structures; Design; Finance; Highways; I24: Design of Bridges and Retaining Walls;
- Accession Number: 00625045
- Record Type: Publication
- Report/Paper Numbers: FHWA/TX-91+1210-1, Res Rept 1210-1, CTR 3-5-89/1-1210-1
- Contract Numbers: Study 3-5-89/1-1210
- Files: TRIS, USDOT, STATEDOT
- Created Date: Oct 6 1993 12:00AM