PRESTRESS LOSSES IN IN-SERVICE BRIDGE BEAMS AND REFINEMENT OF PREDICTION METHOD
Long term concrete strains in pretensioned beam members in an experimental bridge were examined for an indication of the loss of prestress in these members under an outdoors in-service condition. The observations were used to test an existing prediction procedure for prestress losses. For the highly prestressed members used in this study, prestress losses were found to be insensitive to the characteristics of the prestressing steel, whether stress-relieved or stabilized. The outdoor specimens showed slightly higher shrinkage and creep strains than their indoor counterparts, however, the differences were not large. The long term concrete strains predicted by the existing procedure agreed reasonably well with the field measured data. A refinement in the estimation of creep strain due to applied loads resulted in improvement agreement. Based on this refinement, prestress may be treated as remaining constant over a short period of time after application of external loads. /FHWA/
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Supplemental Notes:
- Prepared in cooperation with the Department of Transportation, Federal Highway Administration.
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Corporate Authors:
Lehigh University
Fritz Engineering Laboratory
Bethlehem, PA United States 18015 -
Authors:
- Huang, T
- Publication Date: 1977-5
Media Info
- Pagination: 75 p.
Subject/Index Terms
- TRT Terms: Beams; Bridge construction; Bridge foundations; Bridges; Concrete; Construction; Creep; Deflection; Forecasting; Prestressed concrete; Prestressing; Pretensioning; Shrinkage; Strain (Mechanics)
- Uncontrolled Terms: Concrete beams; Prestress loss
- Old TRIS Terms: Concrete creep; Strains
- Subject Areas: Bridges and other structures; Construction; Highways;
Filing Info
- Accession Number: 00178809
- Record Type: Publication
- Source Agency: Federal Highway Administration
- Report/Paper Numbers: FHWA-PA-RD-71-9-3, FCP 45F2-112, Report 382.5
- Contract Numbers: Res. Proj 71-9
- Files: TRIS, USDOT
- Created Date: Sep 14 2003 12:00AM