Probabilistic Models for the Tensile Strength of Corroding Strands in Posttensioned Segmental Concrete Bridges
Publication: Journal of Materials in Civil Engineering
Volume 22, Issue 10
Abstract
The presence of air voids, moisture, and chlorides inside tendon systems on segmental posttensioned (PT) bridges has been cited as a reason for the early age corrosion and failure of strands in these bridges. This paper develops probabilistic models to predict the time-variant tension capacity of PT strands exposed to wet-dry conditions. A total of 384 unstressed and 162 stressed strand test specimens were exposed to various void, moisture, and chloride conditions for 0, 12, 16, and 21 months; the residual tension capacities of the strands were then determined. Using these experimental data, a Bayesian approach is used to develop probabilistic capacity models for unstressed and stressed strands. The tension capacities of stressed strands under potential void, wet-dry, and chloride conditions in the field are predicted using the developed models. Probabilistic time-variant models are formulated in such a way that they can be updated by other researchers using additional information from the testing of unstressed strands only, avoiding expensive and cumbersome testing of stressed strands. The mean absolute percentage errors of these models are less than 3.2%, indicating good overall model accuracy.
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Acknowledgments
This research was performed at the Texas Transportation Institute (TTI) and Zachry Department of Civil Engineering, Texas A&M University (TAMU), College Station, Tex., through a sponsored project from the Texas Department of Transportation (TxDOT), Austin, Tex. This support is much appreciated. The writers acknowledge the support from Keith Ramsey (Program Coordinator), Jaime Sanchez (Project Director I), Maxine Jacoby (Project Director II), German Claros (Project Director III), Brian Merrill (Project Director IV), Dean Van Landuyt, Kenneth Ozuna, Steve Strmiska, Tom Rummel, and other TxDOT engineers. The writers acknowledge Jeff Perry and Matt Potter of the High Bay Structural Materials Laboratory; Scott Crauneur of the Zachry Department of Civil Engineering; and Duane Wagner, Cheryl Burt, Scott Dobrovolny, Robert Kocman, and Gary Gerke of TTI for their assistance during the experimental phase of this research. The writers also acknowledge the assistance from Daren Cline, Ramesh Kumar, and Byoung Chan Jung during the analytical phase of this research.
References
AASHTO LRFD. (2008). AASHTO LRFD bridge design specifications, American Association of the State Highway and Transportation Officials, Washington, D.C.
ACI. (2003). “222R-03—Protection of metals in concrete against corrosion.” ACI Communication 222, Document No. 22203, American Concrete Institute, Detroit.
Akgül, F., and Frangopol, D. M. (2004). “Lifetime performance analysis of existing prestressed concrete bridge superstructures.” J. Struct. Eng., 130(12), 1889–1903.
ASBI. (2000). American Segmental Bridge Institute Grouting Committee: Interim statement on grouting practices, American Segmental Bridge Institute, Phoenix.
ASTM. (2006). “Standard specification for steel strand, uncoated seven-wire for prestressed concrete.” ASTM A416, West Conshohocken, Pa.
Box, G. E. P., and Tiao, G. C. (1992). Bayesian inference in statistical analysis, Addison-Wesley, Reading, Mass., 113–122.
FDOT. (2001a). “Mid-bay bridge post-tensioning evaluation—Final report.” Rep. Prepared for Corven Engineering, Inc., Florida Dept. of Transportation, Tallahassee, Fla.
FDOT. (2001b). “Sunshine skyway bridge post-tensioned tendons investigation.” Rep. Prepared for Parsons Brinckerhoff Quade and Douglas, Inc., Florida Dept. of Transportation, Tallahassee, Fla.
Gardoni, P., Der Kiureghian, A., and Mosalam, K. M. (2002b). “Probabilistic capacity models and fragility estimates for reinforced concrete columns based on experimental observations.” J. Eng. Mech., 128(10), 1024–1038.
Gardoni, P., Pillai, R. G., Hueste, M. D., Reinschmidt, K., and Trejo, D. (2009). “Probabilistic capacity models for corroding posttensioning strands calibrated using laboratory results.” J. Eng. Mech., 135(9), 906–916.
Gardoni, P. G., Der Kiureghian, A., and Mosalam, K. M. (2002a). “Probabilistic capacity models and fragility estimates for bridge components and systems.” PEER Rep. No. 2002/13, Pacific Earthquake Engineering Research Center, Dept. of Civil Engineering, Univ. of California, Berkeley, Calif.
Kovač, J., Leban, M., and Legat, A. (2007). “Detection of SCC on prestressing steel wire by the simultaneous use of electrochemical noise and acoustic emission measurements.” Electrochim. Acta, 52, 7607–7616.
Melchers, R. E. (2003). “Modeling of marine immersion corrosion for mild and low-alloy steels—Part 1: Phenomenological model.” Corrosion (Houston), 59(4), 319–334.
NCDC. (2008). “National Climatic Data Center (NCDC).” ⟨www.ncdc.noaa.gov⟩ (Nov. 1, 2008).
NCHRP. (1998). “Durability of precast segmental bridges.” NCHRP Web Document No. 15, Project 20–7/Task 92, R. W. Poston and J. P. Wouters, eds., National Cooperative Highway Research Program, Transportation Research Board, National Research Council, Washington, D.C.
Pillai, R. G. (2009). “Electrochemical characterization and time-variant structural reliability assessment of post-tensioned, segmental concrete bridges.” Ph.D. thesis, Zachry Dept. of Civil Engineering, Texas A&M Univ., College Station, Tex.
Poston, W. R., Frank, K. H., and West, J. S. (2003). “Enduring strength.” Civil Engineering, American Society of Civil Engineering, 73(9), 58–63.
Proverbio, E., and Longo, P. (2003). “Failure mechanisms of high strength steels in bicarbonate solutions under anodic polarization.” Corros. Sci., 45, 2017–2030.
PTI. (1998). Acceptance standards for post-tensioning systems, Post-Tensioning Institute, Phoenix.
Sanchez, J., Fullea, J., Andrade, C., and Alonso, C. (2007). “Stress corrosion cracking mechanism of prestressing steels in bicarbonate solutions.” Corros. Sci., 49, 4069–4080.
Schupack, M. (2004). “PT grout: Bleedwater voids.” Concr. Int., 26(8), 69–77.
Trejo, D., et al. (2009a). “Effects of voids in grouted, post-tensioned, concrete bridge construction.” Rep. No. 0-4588, Texas Transportation Institute, Texas Dept. of Transportation, Austin, Tex.
Trejo, D., Pillai, R. G., Hueste, M. D., Reinschmidt, K., and Gardoni, P. (2009b). “Parameters influencing corrosion and tension capacity of post-tensioning strands.” ACI Mater. J., 106(2), 144–153.
Vu, N. A., Castel, A., and Francois, R. (2009). “Effect of stress corrosion cracking on stress-strain response of steel wires used in prestressed concrete beams.” Corros. Sci., 51, 1453–1459.
Woodward, R. J., Cullington, D. W., and Lane, J. S. (2001). “Strategies for the management of post-tensioned concrete bridges.” Current and future trends in bridge design, construction, and maintenance—2, P. C. Das, D. M. Frangopol, and A. S. Nowak, eds., Thomas Telford, London, 23–32.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 22 • Issue 10 • October 2010
Pages: 967 - 977
Copyright
© 2010 ASCE.
History
Received: Jul 25, 2009
Accepted: Mar 4, 2010
Published online: Mar 6, 2010
Published in print: Oct 2010
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